Econar GeoSource DualTEK GV Series User manual

Installation
and
Operating Instructions
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Air Filter
Air Coil
Transformer
Controller
Reversing
Valve
Desuperheater
(Optional)
Controller
Reversing
Valve
Transformer
Scroll
Compressor
Contactor
GeoSource DualTEK Vertical Unit
GeoSource DualTEK Horizontal Unit
Blower
Contactor
Expansion
Valve
Scroll
Compressor
Air Pad
Air Coil
Blower
Air Pad
Licensed under U.S. Patent Number 4,856,578
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TABLE OF CONTENTS
Section Title Page
I. Introduction to ECONAR Heat Pumps
Unit Location/lVlounting
Duct System/Blower
Hydronic Side Heat Exchangers
A. Radiant Floor Heating
B. Baseboard Heating
C. Other Applications
D. TemperatureLimitations
Applications of llydronic Side Heat Exchangens . 5
A. Storage Tanks
B. Hydronic Side Circulators
C. Circulation Fluid
D. Expansion Tanks
E. Application Diagrams
VI. Earth Loop Water Piping
A. Closed Loop Applications
B. Open Loop Applications
1) Open Loop Freeze Protection Switch
2) Water Coil Maintenance
a. FreezeCleaning
b. Chlorine Cleaning
c. Miratic Acid Cleaning
Condensate Drain ....... 12 VII.
VIII. Unit Sizing 13
A. Earth Loop Configuration and Design Water Temperatures
B. Hydronic Side Heat Exchanger Operating Temperatures
C. Building Heat Loss/lleat Gain
D. TemperatureLimitations
IX. Electrical Service t4
t4
24Yolt Control Circuit
A. Transformer
B. Thermostat/Aquastat
C. Controller
1) Blower Operation
2) Earth Loop Pump Initiation
3) CompressorOperation
4) 4-Way Valve Control
5) CompressorLockouts
6) CompressorAnti-Short-Cycle
7) System Diagnostics
8) Forced Air/Hydronic Priority
9) Overflow Detection
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XI. Startup
XII. Service
xIII.
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A. Filter
B. Lockout Lights
C. Preseason Inspection
Thermostat Operation
Troubleshooting Guide For Unit Operation
Troubleshooting Guide For Lockout Conditions
Additional Figures and Tables
18
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26
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XV[. Desuperheater(Optional)
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I. INTRODUCTION TO
ECONAR HEAT PUMPS
ECONAR Energy Systems, Corp. has been producing
geothermal heat pumps in Minnesota for over fifteen
years. The cold winter climate has driven the design of
ECONAR Energy System's heating and cooling
equipment to uhat is known as a "Cold Climate"
geothermal heat pump. This cold climate technology
focuses on maximizing the energy savings available in
heating dominated regions without sacrificing comfort-
Extremely efficient cooling, dehumidification and
optional domestic hot water heating are also provided in
one neatly packaged system.
Geothermal heat pumps get their name from the transfer
of heat to and from the earth. The earth coupled heat
exchanger (geothermal loop) supplies the source energy
for heating and absorbs the discharged energy from
cooling. The system uses a compression cycle, much like
your refrigerator, to collect the earth's energy supplied by
the sun and uses it to heat your home. Since the process
only moves heat and does not create it, the efficiencies are
three to four times higher than the most efficient fossil
fuel systems.
ECONAR produces three types of geothermal heat
pumps: forced air heat pumps, which transfer heat from
water to air; hydronic heat pumps, which transfer heat
from water to water; and GeoSource DualTEK heat
pumps, which incorporate the hydronic heating of a water
to water unit into a forced air unit. This guide discusses
the GeoSource DualTEK unit (U.S. Patent Number
4,8s6,878).
Safety and comfort are both inherent to, and designed into
ECONAR Energy System's geothermal heat pumps.
Since the system runs completely on electrical energy,
your entire home can have the safety ofbeing gas free.
The best engineering and quality control is built into
every ECONAR heat pump built. Proper application and
correct installation will assure excellent performance and
customer satisfaction.
ECONAR's commitment to quality is written on the side
of every heat pump we build. Throughout the building
process the technicians that build each unit sign their
names to the quality assurance label after completing their
inspections. As a final quality test, every unit goes
through a fulI run test where the performance and
operation is verified in both the heating and cooling
modes. No other manufacturer goes as far as to run a full
performance check to assure system quality.
** IMPORTANT**
Service ofrefrigerant based equipment can be hazardous
due to system pressure and 230 volt electrical energy.
Only trained or qualified service personnel can install,
repair or service refrigerant equipment.
2
I Warning - Turn offthe main switches before
performing service or maintenance to this unit. Electrical
shock can cause personal injury. The installer is
responsible to see that all local electrical, plumbing,
heating and air conditioning codes are followed.
aNote: The Hydronic side of the GeoSource DualTEK
utilizes a single-walled heat exchanger, and is not
intended for use with potable water.
II. UNIT LOCATION/
MOUNTING
Locate the unit in an indoor area where the ambient
temperature will remain above 45oF. Servicing of the
heat pump is done primarily from the front. Rear access
is very desirable and should be provided when possible.
A field installed drain pan is required under the enrire unir
where accidental water discharge could damage
surrounding floors, walls or ceilings.
VCAUTION -Do nor tip units on rheir side during
transportation or installation, or severe internal damage
rr[ry occur.
Units must be mounted on a vibration-absorbing pad
slightly larger than the base to provide isolation between
the unit and the floor. Water supply pumps should not be
hard plumbed directly to the unit with copper pipe; this
could transfer vibration from the water pump to the
refrigeration circuit, causing a resonating sound. Hard
plumbing could also transfer vibration noise from the unit
through the piping to the living space"
cNote: Keep all doors and screws installed on the unit
while moving the unit and installing ductwork. This will
help ensure that the unit stays square, allowing for easier
removal of the doors after the ductwork is attached.
VCAUTION - Before driving screws into the cabinet,
check on the inside of the unit to be sure the screw will
not hit electrical or refrigeration lines.
III. DUCT SYSTEM/BLOWER
For the duct system, metal ductwork should be used.
Flexible connectors are required for discharge ard return
air duct connections on a metal duct system. For
acceptable duct sizes, see Table 1.
Ifthe duct system is installed in an uninsulated space, the
metal ductwork should be insulated on the outside to
prevent heat loss and to absorb noise.
If the unit is connected to existing ductwork, this
ductwork must have the capacity to handle the air volume
required by the heat pump. Undersized ductwork will
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cause noisy operation and poor operating efficiencies due
to lack of airflow.
The standard GeoSource DualTEK (-Gxxxx-x-Dx0x)
heat pumps use a 230 Volt three-speed blower. For
maximum airflow, the blower should be on high speed.
Moving the wire on the fan terminal strip can change the
fan speed. For blower data and factory settings, see Table
2._
An optional variable speed ECM blower motor is
available on the GeoSource DualTEK (Gxxxx-x-DxVx)
series heat pumps. These motors convert 230 Volt AC
power to DC power internally. The DC power can then
be modulated to tum the motor at a variety of speeds.
The blower's speed is modulated based on what the
thermostat is calling for. If the thermostat is calling for
only the FAN to operate, the blower will put out a low
amount of airflow in cubic feet per minute (CFM). This
low CFM output will gently circulate air throughout the
house, eliminating hot or cold spots, and actually reduce
the need for mechanical heating or cooling at certain
times of the year. The blower can supply this minimal
CFM output with a very low electrical usage.
When the thermostat calls for first stage forced air heating
or cooling, the fan speed slowly begins to increase speed.
Because of the slow ramping of the blower speed, full
speed on first stage may not be achieved until nearly four
minutes have elapsed from the initial call. This enables
the blower to have very quiet starts, and helps minimize
cold blasts of air in the winter. It also provides increased
dehumidification in the summer and warmer, more
comfortable discharge air in the winter. When the
thermostat calls for second stage heating, it will bring the
fan speed up to high speed. The fan speeds ofthe
GeoSource DualTEK heat pumps are factory set to
provide the highest efficiency at each stage of operation,
but may be adjusted slightly in the field to increase
comfort. These settings are shown in Table 3.
The controller provides a total of 12 fan speed set points.
There are four different CFM outputs in each of the three
fan speed ranges (Low, Medium, and High). These CFM
outputs are factory set, and should notbe changed in the
field. There is an Adjust seuing, which allows the blower
to be operated at+l- llVc ofthe factory setting. For
example, if the Adjust tap is set to the '1", all the speeds
will operate at90Vo of the factory setting. If the Adjust
tap is set to the "+", all the speeds will operate at ll\Vo of
the factory setting. The Adjust tap is the only tap on the
Blower Speed Controller that should ever be moved from
the factory setting. The blower motor also provides
internal circuitry that will try to maintain the setpoint
CFM when changes occur in the external static pressure,
such as the frlter getting dirty over time. The motor does
this by increasing its torque output to compensate for
external resistance changes.
The blower is also programmed to provide soft starting to
reduce air noise, delays after compressor shutdown to
distribute all the heat output from the compressor to the
heated space, and ramped speed changes. All these
features are designed for quiet, comfortable, efficient
operation.
eNote: The blower will not operate properly if
ductwork is not attached. The ductwork supplies static
pressure to give the blower motor a load to work against.
Blower motors may overheat if run for an extended period
of time without ductwork attached.
Table 1- Duct Chart
Tables calculated 0.05 to of water friction per At these duct design with the pressure drop the filter,
3
4' 4x4
54x5,4x6
6" 4x8,4x6
7" 4x10,5x8, 6x6
8" 5x10, 6x8,4x14,7x7
9' 6x10, 8x8,4x16
10" 6x74,8x10,7x12
10" 6x20, 6x16,9x10
12" 6x18, 10x10,9x12 10' '7x7
12" 6x20,8x14,9x12,10x11 10" 9x10. 8xl 2
10" 10x10,6x18, 8x12,7x14
t2" 6x20,7x18,8x16, 10x12
12" 8x18, 9x1 5, 10x14, L2xt2
14" 10x1 8, 12114,8x24
16' 10x20,12x18,14x15
16', lOtt 5, 12x20, 14x1 8, 15x16
18" 10x30, 15x18, 14x20
20" 1 0x35, 1 510, 16x19, 12x30, 14y25
20" 10x40, 12x30, 15x25, 18x20
22" 1 0x45, 15x28, 18x22, 2Ox20
the total design extemal static pressure is 0.20 inches of water. Normal airflow at 0.20 inches of water should then be used for these calculations.
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Table 2 - Fan Performance Data
*Denotes Factory Setting
Table 3 - Airflow
IV. HYDRONIC SIDE HEAT
EXCHANGERS
A. Radiant Floor Heating
Hydronic side heat exchangers can be a variety of
different types. Probably the most popular form of
hydronic heat exchangers is radiant floor heat tubing.
Radiant floor heating gives excellent comfort and very
high efficiencies by supplying low temperature water to
the floor slab, and keeping the heat concentrated evenly
near the floor. Radiant floor systems heat the occupants
and surfaces directly with radiant energy. Forced air
heating moves heated air around the building, which
transfers the heat to the occupants. Air movement can
create drafts, temperature stratification, and air rising to
the ceiling, which must be considered when designing
heating systems. Always remember that hot air rises, heat
does not.
Radiant floor heating usually consists of 1/2 inch plastic
tubing, approximately one linear foot of pipe per square
foot of floor space. This value is doubled for one pass
along the outside walls to concentrate more heat in this
area. The tubing is generally laid into the concrete slab
floor of the building. New construction techniques have
also made installation into wood floors and suspended
floors possible. The amount and spacing of the tubing is
sized to meet the capacity of the space at a certain fluid
temperature inside the tubing. To optimize the efficiency,
the fluid temperature inside the tubing should be
maintained as low as comfortably possible.
The type of floor covering and the spacing of the pipe in
the floor have the greatest effect on operating fluid
temperature. Table 4 gives a rough estimate of expected
operating temperatures for specific floor coverings:
Table 4 -Floor
ECONAR designs the hydronic side of the GeoSource
DualTEK line using a l l5oF leaving water temperature
design point. This leaving water temperature is the ideal
maximum fluid temperature for radiant floor systems.
Operating temperatures higher than this would result in an
uncomfortable hot feeling in the conditioned space. In
fact, boilers connected to radiant floor heating systems
must be restricted to a 115oF maximum operating
temperature by mixing valves or other control devices.
Distributors of radiant floor heat exchanger tubing can
help size the length of pipe and fluid temperature required
for your specific radiant floor heat exchanger
applications. Be sure to include insulation under the slab
and around the perimeter. Two inches of polystyrene
under the slab and two to four inches on the perimeter
down to a four-foot depth are requted. This insulation
reduces the heat loss to the ground and increases the
response time of the heating system. Building insulation
is important in radiant floor heating, as in other methods
ofheating. Poorly insulated buildings can result in higher
floor temperatures needed to heat the building, which
could exceed the level of human comfort.
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Medium*
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1010
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985
805
915
960
740
840
895
Low
Medium
High*
1325
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1275
1450
1625
1235
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1375
1500
1 165
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1275
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I 105
1245
1360
1055
I 185
1305
Low
Medium
High*
1500
1700
1900
1450
1645
1850
1,410
1595
1800
1360
1555
1740
1325
1500
1680
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1480
1625
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1590
1210
1380
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Medium*
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1900
2220
24tO
1850
2185
2370
1800
2150
2325
1750
2110
2250
1690
2050
2200
I 660
2000
2150
1600
1960
2110
1560
1880
2030
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Night setback thermostats are not recommended on
radiant floor systems due to the response time of the slab.
B. Baseboard Heating
Another application of hydronic heating is finned tube
baseboard heating. This is the same tubing used with
boilers with one major difference. The discharge
temperature of a boiler is much higher than geothermal
heat pumps. The heat pump system should be sized at
115oF hydronic leaving water temperature to maintain
efflrciency. At a l25oF leaving water temperature, the heat
pump is at a maximum operating temperature and may
start to trip offon high head pressures. Standard 3/4"
finned tube baseboard conductors have an average output
of 230 Btuhfft at 120T hydronic leaving water
temperature. In most cases there is not enough perimeter
area in the conditioned space to allow for the required
length of tubing to handle the entire heating load. There
have been successful installations using baseboard heating
as supplemental heating using the forced air side of the
GeoSource DualTEK unit to satisfy the heating load.
Cast iron radiators have also been used successfully. If
these radiators are rated for an output of70 Btuh/square
inch at a 130oF hydronic leaving water temperature, they
work well with geothermal systems. Although the
radiator may be rated at 130'F, the system should still
operate at the standard 115"F leaving water temperature
of the hydronic side of the heat pump.
C. Other Applications
Additional open loop hydronic applications such as
outdoor swimming pools, hot tubs, whirlpools, tank
heating, etc. are easily sized based on heat exchanger
operating temperature and flow. The worksheet in
Appendix I was taken from the ASHRAE 95
Applications Manual and can be used for outdoor
swimming pool sizing. In many instances, sizing a heat
pump to these applications comes down to recovery time.
The larger the heat pump (within reason to avoid short
cycling) the faster the system recovery time will be.
eNote: Installing a plate heat exchanger (see Figure 3
for an example) between the heat pump and an open
system is required when corrosive fluid is used in the
open loop, especially on swimming pools where pH
imbalance can damage the heat pump. eNote: Expect
the maximum operating temperature of an indirect
coupled application to be l0oF below the maximum
operating temperature of the heat pump.
Other forms of closed loop systems such as indoor
swimming pools, pretreated fresh air systems, snow melt
systems, and valance heating systems are also very
corrmon with GeoSource DualTEK heat pumps. The
sizing of the heat pump to these systems is more precise
and information from the system manufacturer is
required.
V.APPLICATIONS OF
HYDRONIC SIDE HEAT
EXCHANGERS
This section deals with some common practices used
when coupling the hydronic side of an ECONAR
GeoSource DualTEK heat pump to the space
conditioning heat exchanger. There are so many possible
applications for these systems that they cannot all be
covered in this text. Hopefully these ideas can help in
many of your system designs.
cNote: Actual systems must be constructed to all
appropriate codes and according to accepted plumbing
practices.
A. Storage Tanks
Coupling the hydronic side of the heat pump to the space
conditioning heat exchanger through a water storage tao_k
is very common. In fact, the only instance where these
storage tanks are not recommended is when the heat
pump is coupled to a large heat exchanger capable of
absorbing the entire heating capacity of the heat pump
(see Figure 2). In applications rhat use multiple smaller
zones, storage tanks absorb the relatively large amount of
energy supplied by the heat pump, in order to provide
longer run times and less compressor cycling for the heat
pump. Storage tanks also serve to dispense energy in
small amounts so that the conditioned zones have time to
absorb heat without requiring high discharge water
temperatures. Insulated hot water heaters are commonly
used for storage tanks.
cNote: While all hot water tanks are insulated on the
top and sides, many do not have insulation on the bottom.
An insulated pad beneath uninsulated tanks will reduce
energy loss to the floor.
When properly sized, a storage tank eliminates many
problems with multiple zone hydronic systems. These
problems include excessive leaving water temperature if a
single zone cannot dissipate heat quickly enough and
hydronic flow reduction through the heat pump when only
one zone is calling. This may occur because the hydronic
side circulating pump is normally sized to provide the
heat pump's required flow with all zones calling. When
sizing storage tanks to the heat pump, a good rule of
thumb is ten gallons of storage tank per ton of hydronic
capacity.
The tank temperature can be controlled with a simple
aquastat or a setpoint controller. The setpoint controller
senses tank water temperature and outside air temperature
to increase the tank temperatwe as the outside air
temperature goes down. This confrol scheme provides the
highest heating efficiencies by requiring the lowest
possible water temperature to heat the space. Setting the
optimal design temperatures in the controller is difficult,
5
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and the simple aquastat does have its advantages. To help
in setpoint control, the following equation can be used.
Reset Ratio = Design Water Temo - Indoor Design Temo
Indoor Design Temp - Outdoor Design Temp
Always check local codes to be sure hot water heaters can
be used as storage tanks. Using the electric elements in
the-tank as a secondary heat source to the heat pump is
app'ealing in some applications, but special UL listing is
required by many loca1 codes. Specially listed hot water
heaters are available.
B. Hydronic Side Circulators
Hydronic circulator pumps transfer the energy supplied
by the hydronic side of ECONAR's GeoSource
DualTEK heat pumps to the space conditioning heat
exchanger. When selecting a circulator, be sure to select
a quiet operating pump with the ability to supply the
required flow rate at the system pressure drop. The
circulator supplying the heat pump should be placed in
the water supply line into the unit to provide the best
pump performance. Individual zone circulators should
also be placed in the supply lines of the heat exchangers
they serve (Figure 3). These pumps are often used as the
on/off conuol mechanism for the zone they supply. Zone
valves are also commonly used for this purpose using a
common pump (shown in Figure 1).
cNote: Select a common pump at the total flow of all
the zones and the highest pressure drop ofany one
parallel zone.
Small Grundfos pumps (230 VAC) can be used as
circulator pumps. These pumps are impedance protected
and do not require additional fusing if powered directly
from the heat pump, since the heat pump is rated to accept
up to a 1/3 horsepower circulator. If impedance protected
pumps are not used, inline fuses should be supplied
according to code.
Pumps must be sized to provide the required flow to a
heat exchanger at its corresponding pressure drop. This
pressure drop can be calculated from the total pressure
drop through the piping, added to the pressure drop of the
space conditioning heat exchanger. The hydronic side
pressure drop through each particular heat pump is listed
in Table 5. This table can be used for sizing the
circulating pump between the hydronic side of the heat
pump and a storage tank.
Table 5 -
This table represents the minimum pump sizing required
to supply the heat pump's required hydronic side flow rate
at the pressure drop of the heat pump and 30 feet of 3/4"
type K copper tubing or combination of elbows and pipe.
A common problem with circulator pumps is trapped air
in the system. This air accumulates in the suction port of
the circulator causing cavitation in the pump, which leads
to premature pump failure and noisy operation. The air
can be eliminated by completely purging the system or by
placing an air separator in the plumbing lines.
The entire system must be purged of air during initial
installation and pressurized to a 10-25 psi static pressure
to avoid air entering the system. This initial static
pressure may fluctuate but should always remain above
zero. If a leak in the system allows the static pressure to
drop, the leak must be repaired to assure proper system
operation. Air contilually entering the loop can cause
corrosion, bacteria, or pump cavitation.
The hydronic side circulator supplying the heat pump
should be controlled to run only when the compressor is
also running. If the circulator pump is allowed to
circulate cold water through the system during offcycles,
the refrigerant in the heat pump will migrate to the
hydronic side heat exchanger. This can cause heat pump
starting problems.
C. Circulation Fluid
The fluid circulating through the hydronic side of the
GeoSource DualTEK heat pump system is the transfer
medium for the heating being supplied to the conditioned
space. Selection of this fluid is very important. Water is
the most readily available fluid but has the drawback of
expansion during freezing which can damage the system.
Extended power intemrption to a structure or the
disabling of an outside zone (such as a garage floor)
provides an opportunity for freezing of the circulating
fluid.
Antifreeze must be used whenever the possibility of
freezing exists from the environment. A propylene glycol
based antifreeze (readily available through HVAC
wholesalers) and water solution is recommended.
Methanol based antifreeze is not recommended for use on
any hydronic system where heat is being added to the
system for structural heating purposes. Freeze protection
for the hydronic side fluid down to 20oF (20Ea propylene
glycol by volume in water) is recommended for most
indoor applications (see Chart 1). Forry percent
propylene glycol in water (-5oF freeze protection) is
recommended by radiant tubing manufactures for snow
melt applications, in order to protect the tubing from
expansion in outdoor applications. Using over 4A7o n
hydronic side applications can cause pumping problems
due to high viscosity.
The water being added to the system should have 100-
PPM grain hardness or less. If poor water conditions
6
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exist on the site, softened water is recommended, or
acceptable water should be brought in. Bacteria or algae
growth in the water is a possibility, especially bacteria or
algae that thrive at the particular temperatures produced in
the heating system. This growth can cause buildup on
hydronic side heat exchanger surfaces, reducing the
efhciency of the system or causing the heat pump to run
at higher head pressures and possibly lock oul Adding a
gallon of bleach or boiler system conditioner can reduce
the possibility of growth and clean up visual flow meters
and other components in the system.
Chart I -Propylene GlycoVWatJSolution Freeze point
VolurDi * proprl.m Brycol h Wet.,
D. Expansion Tanks
Expansion tanks must be used in the hydronic side of the
GeoSource DualTEK heat pump system to absorb the
change in pressure ofthe closed system due to the change
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in temperature when heat is supplied to the system.
Diaphragm-type expansion tanks should be used. The
diaphragm in these tanks is filled with pressurized air,
which expands, or contracts to maintain a constant overall
system pressure as the fluid in the system expands with
increasing temperature. Use EPDM diaphragm tanks
because they are compatible with glycol-based antifreeze
fluids (butyl rubber diaphragms will slowly dissolve with
glycol-based antifreezes).
Tanks from 1 to 10 gallons are generally used with heat
pump systems in residential and light commercial
applications. Expansion tanks should be installed in the
system near the suction of the circulator pump whenever
possible. This maintains positive pressure at the
circulator pump and reduces the highest working pressure
of the system. A pressure gauge near the inlet of the
expansion tank gives a good indication of how the system
is operating.
Pressure relief valves are required on all hydronic
applications. A 30 psi relief is adequate if the system is
operated at 12 to 15 psi pressure. If a hot water heater is
used for a storage tank, the 150 psi pressure relief may be
acceptable (check local codes).
E. Application Diagrams
Figures 1 through 3 show the components ofa
GeoSource DualTEK heat pump system discussed above
used in some common applications. These frgures by no
means represent all the possible heat pump applications,
but they do show some important principals that can be
applied to any system.
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Cieulatim pup (230
Figure 1-GeoSource DualTEK Heat Pump - Multizone Hydronic Heating and Forced Air Heating/Cooling

Figure 2 - GeoSource DualTEK Heat Pump - Single Zone Hydronic Heating and Forced Air Heating/Cooling
Notc: Always use oopperpipe
whm plumbing hydronic system
NotE: Conc?tual drawing only. Check local
codcs and ue proper plmbing prooedurcs.
Note: Conoeptual drawing only. Cheok local
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Zone oiroulathg pmpr
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md powsr supply to stsrt
zonc cirwlating pumps
Intomcdiate pool
heat exchmger Rsdimt floor zonq
Note: Expect a 1 OoF temperature differential between supply storage tank and open hydronic loop when transfering heat with intermediate heat exchanger.
Figure 3 - GeoSource DualTEK Ileat Pump - Multizone Hydronic Heating, Forced Air lleating/Cooling, and
Intermediate Pool Heat Exchanger
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comeoted to R ed
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VI. EARTH LOOP WATER
PIPING
Since water is the source of energy in the wintertime and
the energy sink in the summertime, good water supply is
possibly the most important requirement of a geothermal
heat pump system installation. There are two cornmon
types of water supplies, closed loop systems and open
loop systems.
A. Closed Loop Applications
A closed loop system recirculates the same
water/antifreeze solution through a closed system of
underground high-density polyethylene pipe. As the
solution passes through the pipe, it collects heat (in the
heating mode) that is being transferred from the relatively
warm surrounding soil through the pipe and into the
relatively cold solution. The solution is circulated to the
heat pump, which pulls heat out of the solution, and then
back through the ground to exffact more heat from the
earth.
The GeoSource DualTEK is designed to operate on
either vertical or horizontal closed loop applications.
Vertical loops are q,pically installed with a well drilting
rig up to 200 feet deep or more. Horizontal systems are
tJpically installed with excavating or trenching equipment
approximately six to eight feet deep, depending on
geographic location and length ofpipe used" Earth loops
must be sized properly for each particular geographic
area, soil type, and individual capacity requirements.
Contact your local installer or ECONAR's Customer
Support for loop sizing requirements in your area.
Since normal wintertime operating entering water
temperatures (EV/T) to the heat pump are from 25oF to
32oF, the solution in the earth loop must include
antifreeze. GTF and propylene glycol are common
antifreeze solutions. GTF is methanol-based antifteeze,
which should be mixed 50Vo withwater to achieve'freeze
protection of 10oF. Propylene glycol antifreeze solution
should be nrxed 25Vo with water to obtain a 15oF freeze
protection. DO NOT mix more than25Vo propylene
glycol with water in an attempt to achieve a lower than
15oF freeze protection, since more concentrated mixtures
of propylene glycol become too viscous at low
temperatures and cannot be pumped through the earth
loop. Insufficient amounts of antifreeze may result in a
freeze rupture of the unit, and can cause unit shutdown
problems during cold weather operation (when the heat
pump experiences the longest run time) due to loop
temperatures falling below tlrre freeze protection of the
loop solution.
Flow rate requirements for closed loops are higher than
open loop systems because water temperatures supplied to
the heat pump are generally lower (see Table 6). Between
2.5 to 3.0 gallons per minute (GPM) per ton are required
for proper operation of the heat pump and the earth
coupled heat exchanger.
TOIFROM
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IN
OUT
PuopPAK Pre$sur€/
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lt
il
9
Figure 4 - Closed Loop Water Plumbing
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Table 6 -Side Flow Rates
Pressure/Temperature (P/T) ports should be installed in
the entering and leaving water lines of the heat pump on a
closed loop system (see Figure4). A thermometer can be
inserted into the P/T ports to check entering and leaving
water temperatures. A pressure gauge can also be
inserted into these P/T ports to determine the pressure
differential between the entering and leaving water. This
pressure differential can then be compared to the
specification data on each particular heat pump to
determine the flow rate of the svstem.
A PumpPAKrM that is individually sized for each
application can supply pumping requirements for the
earth loop fluid. The PumpPAKrM can also be used to
purge the loop system. The PumpPAKrM is wired directly
to the contactor and operates whenever the compressor
runs (see Electrical Diagrams - Figures 8 and 9). If a
PumpPAKrM is not used, a separate pump can be used
which is energized with a pump relay (note: electrical
code will require a fused disconnect for pumps other than
PumpPAKsrM).
Filling and purging a closed loop system are very
important steps to assure proper heat pump operation.
Each loop must be purged with enough water flow to
assure a two feet per second flow rate in each circuit in
the loop. This normally requires a lYz to 3 HP high head
pump to circulate fluid through the loop to remove all the
air out of the loop and into a purging tank. Allow the
pump to run 10 to 15 minutes after the last air bubbles
have been removed. Enough antifreeze must be added to
give a 10oF to 15oF freeze protection to the earth loop
system. This amount should be calculated and added to
the loop after purging is complete. After antifreeze has
been installed it should be measured with a hydrometer,
refractometer or any other device to determine the actual
freezing point of the solution. Remember that a low
arftifreeze level will lock the heat pump out on low
pressure during wintertime operation.
The purge pump can be used to pressurize the system to
an initial static pressure of 30-40 psi. Make sure the
system is at this pressure after the loop pipe has had
enough time to stretch. In order to achieve the 30 to 40
psi initial pressure, the loop may need to be pressurized to
60 to 65 psi. This static pressure will fluctuate from
heating to cooling season, but the pressure should always
remain above zero so circulation pumps do not cavitate
and air cannot be pulled into the system. SFor
information regarding earth loop installations contact your
local installer, distributor or factory representative.
B. Open Loop Applications
An open system gets its name from the open discharge of
water after it has been used by the heat pump. A well
must be available that can supply all of the water
requirements (see Table 6) of the heat pump along with
any other water requirements drawing off that same well.
The well must be capable of supplying the heat pump's
required flow rate for up to 24 hours per day on the
coldest winter day.
Figure 5 shows the necessary components for water
piping of an open system. First, a bladder type pressure
tank with a "draw down" of at least lYz times the well
pump capacity must be installed on the supply side of the
heat pump. Shut off valves and boiler drains on the
entering and leaving water lines are necessary for future
maintenance issues. A screen strainer is placed on the
supply line with a mesh size of 40 or 60 and enough
surface area to allow for particle buildup between
cleanings.
Pressure/Temperature (P/T) ports are placed in the supply
and discharge lines so that thermometers or pressure
gauges can be inserted into the water stream.
On the well water discharge side of the heat pump, a flow
control valve must be mounted next to the heat pump to
regulate the maximum water flow through the unit. A
solenoid valve is then installed and wired to the accessory
plug (P2) on the controller. This valve will open when
the unit is running and close when the unit stops. A
visual flow meter is then installed to allow visual
inspection of the flow requirements. The flow meter is
useful in determining when maintenance is required. (If
you can't read the flow, cleaning is required. See Water
Coil Maintenance for cleaning instructions.)
Schedule 40 PVC piping, copper tubing, polyethylene or
rubber hose can be used for supply and discharge water
lines. Make sure line sizes are large enough to supply the
required flow with a reasonable pressure drop (generally
1" diameter minimum). NOTE: Do not use plastic
female fittings with metal male fittings, or fractures may
result in the female fittings. Always use plastic male into
steel female!
Water discharge is generally made to a drain field, stream,
pond, surface discharge, tile line, or storm sewer.
VCAUTION: Using a drain field requires soil
conditions and adequate sizing to assure rapid percolation,
or the required flow rates will not be achieved. Consult
local codes and ordinances to assure compliance. p
pf discharge water to a septic system.
10
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Figure 5 - Open Loop Water Plumbing
The heat pump should never be operated with flow rates
less than specified. [.ow flow rates or no flow may result
in freezing water in the water to refrigerant heat
exchanger. This will cause the unit to shut down on low-
pressure lockout. Ifthe unit locks out, verify that the unit
has the required flow and reset the unit by shuming off
power to the unit for one minute. VDO NOT continually
reset the unit, if the unit locks out more than once call
your service professional. SContinued reset of the unit
car, freeze water inside the water coil to the point of
rupturing the water coil.
L. Open Loop Freeze Protection Switch
Heat pump installations on open loop systems, using a
non-antifreeze protected water source during the heating
mode, reouire the use of afreeze protection switch. If the
water supply to the heat pump is interrupted for any
reason, continued operation of the compressor would
cause the water remaining in the water-to-refiigerant heat
exchanger to freeze and rupture the copper inner tube.
The freeze protecrion switch (ECONAR Parr # 75-1028)
will shut the unit down before freezing can occur and
protect the heat pump against loss of flow. A freeze
protection switch must be field installed on open loop
GeoSource DuaITEK heat pumps before the waranty
can be registered on the heat pump. The switch mounts
on the compressor's suction line and is wired to terminals
1. on the controller (from X to FP1). After the freeze
protection switch is installed, the J3 jumper must be
removed from the controller to activate the switch. The
low pressure switch now locks the unit off at 35 psi
pressure in the heating mode.
2. Water Coil Maintenance
Water quality is a major concern for open systerns.
Problems can occur from scaling, particle buildup,
suspended solids, corrosion, pH levels outside theT-9
range, or biological growth. If poor water quality is
known to exist in your area, a cupro-nickel water coil may
be required when ordering the system, or installing a
closed loop system may be the best alternative. Water
coil cleaning on open loop systems may be necessary on a
regular basis. Depending on the specific water quality
issue, the water coil can be cleaned by the following
methods:
a. Freeze.Cleaning (Scale deposits, particle
buildup)
I. Before using the freeze cleaning procedure, verify that
it needs to be done. Answer the following questions to
determine if servicing is required.
1. Determine and verify that the required water flow
rate in GPM is both present and correct.
2. Determine the temperature differential of the
water. Under normal conditions, there should be a
temperature difference ofabout 10-15 degrees
between the supply side and discharge side. Ifthe
temperature difference is 8 degrees or less,
consideration should then be given to cleaning the
water coil heat exchanger.
I
J
11
I
I

II. If cleaning of the water coil is indicated, please
carefully follow the steps listed below to utTlize the freeze
cleaning method.
1. Turn off the heat pump and its water supply.
2. Open a plumbing connection on the water supply
side, ifpossible, to break the system vacuum and
allow easier drainage of the system and water coil.
3. Drain the water out of the system and water coil
via the boiler drains on the entering and leaving
water lines, and the drain on the heat exchanger.
SWARNING!! 9 FAILURE TO COMPLETELY
DRAINTHE WATER COIL HEAT EXCHANGER
COULD POSSIBLY RESULT INA FREEZE
RUPTURE!
4. Set the thermostat to "Heat" to start the heat pump
hr the heating mode and quickly freeze the coil.
5. Allow the heat pump to run until it automatically
shuts off on low pressure and then turn the
thermostat to the "Off' position.
6. Recap the water coil drain and tighten any
plumbing comections that may have been
loosened.
7. If so equipped, open the field installed drain cock
on the water discharge side of the heat pump, and
install a short piece of rubber hose to allow
drainage into a drain or bucket. A drain cock on
the discharge side allows the water flow to bypass
the solenoid valve, flow valve, flow metor, or any
other item that may be clogged by mineral debris.
Drainage to a bucket helps prevent the clogging of
drains and allows you to visually determine the
effectiveness of the procedure.
8. Tum on the water supply to the heat pump in order
to start the process of flushing any mineral debris
from the unit.
9. Set the thermostat to "Cool" and start the heat
pump in the cooling mode to quickly thaw out the
water coil.
10. Run the heat pump until the water coil is
completely thawed out and any loosened scale,
mineral deposits, or other debris buildup is flushed
completely from the water coil. Allow at least 5
minutes of operation to ensure ttrat the water coil
is thoroughly thawed out.
1 1. If the water still contains mineral debris, and if the
flow through the unit did not improve along with
an increase in the temperature difference between
the water supply and discharge, repeat the entire
procedure listed above.
12. Reset the heat pump for normal operation.
b. Chlorine Cleaning (Bacterial Growth)
1. Turn the thermostat to the "Off' position.
2. Connect a submersible circulating pump to the
hose bibs on the entering and leaving water sides
of the heat exchanger.
3. Submerse the pump in a five-gallon pail of water
and chlorine bleach mixture. The chlorine should
be strong enough to kill the bacteria. Suggested
initial mixture is I part chlorine bleach to 4 parts
water.
4. Close the shut off valves upsfteam and
downstream of the heat exchanger.
5. Open the hose bibs to allow circulation of the
bleach solution.
6. Start the pump and circulate the solution through
the heat exchanger for 15 minutes to one hour. -
The solution should change color to indicate the
chlorine is killing the bacteria and removing it
from the heat exchanger.
7 " Flush the used solution down a drain by adding a
fresh water supply to the pail. Flush until the
leaving water is clear.
8. Repeat this procedure until the solution runs clear
through the chlorine circulation process.
9. Flush the entire heatpump system with water.
This procedure can be repeated annually, semiannually, or
as often as it takes to keep bacteria out of the heat
exchanger, or when bacteria appears in a visual flowmeter
to the point the flow cannot be read.
Another alternative to bacteria problems is to shock your
entire well. Shocking your well may give longer term
relief from bacteria problems than cleaning your heat
exchanger, but will probably need to be repeated, possibly
every three to five years. tContact a well driller in your
area for more information.
c. Miratic Acid Cleaning (Difficult Scaling
and Particle Buildup Problems)
1. Consult installer due to dangerous nature ofacids.
2. Iron out solutions and de-scaling products are also
useful.
VII. CONDENSATE DRAIN
Condensate traps are built into every GeoSource
DualTEK vertical unit, so an external trap should not be
installed. Vertical units must be level to insure proper
condensate drainage. Horizontal units require an external
condensate trap in order to drain water from the heat
pump. Horizontal units must also be mounted level in
order for the condensate to drain.
3/4"Mnimu
diaq.t'
Air v@t
Het prrp bs€
6" Drop
rfijDua. 3i Rise
To drain with
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Figure 6 - Condensate Drain - Horizontal Units Only
I
I

The condensate line as it leaves the U bend ofthe
condensate trap must be at least 3" below the base ofthe
heat pump. This requires the U bend to be 6,'below the
unit to give the upward portion of the U bend a 3" lift.
The condensate trap should be vented after the U bend.
The condensate line should be pitched away from the unit
a minimum of 1/8" per foot. ff the unit produces an odor
in the cooling mode, the condensate ftap or line may be
plugged, or the unit may not be pitched correctly. Bleach
may be poured down the condensate drain in the heat
pump to kill any bacterial gowth in the condensate line.
V[I. UNIT SIZING
Selecting the unit capacity of a GeoSource DualTEK
geothermal heat pump requires four things:
A) Earth Loop Configuration and Design Water
Temperatures.
B) Hydronic Side Heat Exchanger Operating
Temperatures.
C) Building Heat Loss/Heat Gain.
D) Temperature Limitations.
A. Earth Loop Configuration and
Design Water Temperatures
Loop configurations include the open and closed loop
varieties. Heat pump flow rate requirements vary
depending on loop conhguration (see Table 6). Consult
ECONAR' s Engineering Specifications Manual for
capacities at different loop entering water temperatures
and hydronic leaving water temperatures. Remember to
use the correction factors for GeoSource DualTEK units
found in the Engineering Specifications manual.
2. Open Loop Systems
On an open loop system the design water temperature will
be the well water temperature in your geographic region.
Many cold climates are in the 50oF range for well water
temperature. If your well water temperatures are lower
than 50oF, for instance Canadian well water can be as low
as 43T, the flow rate must be increased to avoid leaving
water temperatures below the freezing point. If well
water temperafures are above 50nF, as in some southern
states where well water temperatures are above 70oF, the
flow rates may need to be increased to dump heat more
efficiently in the cooling mode.
Varying well water temperatures will have little effect on
unit capacity in the cooling mode (since the well is
connected to the heat pump condenser), but can have
large effects on the capacity in the heating mode (since
the well is connected to the evaporator). If well water
temperatures are to exceed 70oF, special considerations,
such as closed loop systems, should be addressed.
B. Hydronic Side Heat Exchanger
Operating Temperatures
The hydronic side heat exchangers discussed in section IV
are designed to operate at a speciflc fluid supply
temperature. This operating temperature will have to be
supplied to the selected space conditioning heat
exchanger by the heat pump. The manufacturers or
distributors of the hydronic side heat exchangers publish
the capacity of their equipment at different operating
temperatures and fluid flow rates. These capacities and
operating temperatures are required to select the heat
pump to be used in the system.
When sizing the hydronic side of the GeoSource
DualTEK heat pump, remember to use the minimum
hydronic loop temperature that will supply the necessary
heating capacity to the conditioned space.
If an intermediate heat exchanger is used between the
closed hydronic loop and the open hydronic loop as
pictured in Figure 3, expect a 10oF operating temperature
difference between the two circuits. For example, if the
direct coupled storage tank is at 120oF, expect the
maximum operating temperature of the open circuit
connected through an intermediate heat exchanger to be
110T. This occurs when connecting open loop
applications to the closed loop systems with plate heat
exchangers or with indirect water heaters.
C. Building Heat Loss/fleat Gain
The space load must be estimated accurately for any
successful HVAC installation. There are many guides or
computer programs available for load estimation
including the ECONAR GeoSource Heat Pump
Handbook, Manual J, and others. After the heat loss/heat
gain is completed, loop EWT's are established, and
hydronic side heat exchanger conditions are determined,
the heat pump can now be selected using the hydronic and
forced air heat pump data found in the Engineering
Specifications. Remember to use the correction factors
for the GeoSource DuaITEK models that are listed in the
Engineering Specifications manual. Choose the capacity
of the heat pump based on both the forced air heating and
cooling loads, and the hydronic heating load.
13
L. Closed Loop Systems
Closed loop systems use a heat exchanger of high density
polyethylene pipe buried underground to supply a
tempered water solution back to the heat pump. Closed
loops operate at higher flow rates than open loops since
the entering water temperature (EWT) is lower. The loop
EWT supplied to the heat pump has a great effect on the
capacity of the unit in the heating mode. Earth loops in
cold climates are normally sized to supply a wintertime
EWT to the heat pump from 32oF down to 25oF, which
minimizes the installation cost of the earth loop and still
maintains proper system operation. The GPM
requirements and pressure drops for loop pump sizing are
shown in Table 6.

D. Temperature Limitations
Be aware of the operating range of the geothermal system
when sizing the particular heat pump. An operating range
of 15oF (minimum for heating) to 110oF (maximum for
cooling) is required for the earth loop side. These limits
have been established based on efficiency limitations and
safety pressure switch limits (25-psi low-pressure cutout
and 400-psi high-pressure cutout). Hvdronic side
limitations have a minimum of 50"F hydronic entering
water temperature and a maximum of 130"F hydronic
leaving water temperature range (entering water to the
hydronic side below50oF gives low head pressures that
drives the suction pressure below cutout conditions).
IX. ELECTRICAL SERVICE
The main electrical service must be protected by a fuse or
circuit breaker, and be capable ofproviding the amperes
required by the unit at nameplate voltage. All wiring
shall comply with the national electrical code and/or any
local codes that may apply. Access to the line voltage
contactor is gained through the knockouts provided on
either side of the heat pump next to the front corner.
Route EMT or flexible conduit with appropriate 3-
conductor wire to the contactor.
9WARNING - The unit must be properlv erounded!9
VCAUTION: Three-phase units ![sf be wired
properly to insure proper compressor rotation. Improper
phasing may result in compressor damage. An electronic
phase sequence indicator must be used to check supply-
wiring phase. Also, the "Wild" leg of the three-phase
power must be connected to the middle leg on the
contactor.
When supplying power to extemal water pumps with the
heat pump's power supply, use only impedance protected
motors. An ECONAR PumpPAKrM can be wired directly
to the contactor and grounded in the grounding lug. A
relay (M6) and terminal block (BP) is supplied in the
electrical box for the hydronic side pump. The relay will
start the pump with a call from the aquastat. The use of
impedance protected pumps eliminates the need for
additional fusing. Do not connect more than a 1/3
horsepower pump to the internal pump relay.
If larger pumps are required, a separate power supply is
required to supply the pump. To start this pump use a24-
volt relay pulled in from the Y and X terminals.
X. 24 VOLT CONTROL
CIRCUIT
The wiring diagrams in Figures 8 and 9 shows the low
voltage controls of the heat pump and some generic
extemal control schemes. This section will break down
the three basic components of the low voltage circuit;
transformer, thermostat/aquastat, and conroller.
A. Transformer
Electrical diagrams are provided in Figures 8 and 9, and
on the electrical box coverpanel ofthe heatpump. An
internal 24-volt,75 VA ffansformer is provided to operate
all control features of the heat pump. Even though the 75
VA transformer is larger than the industry standrlrd 40
VA transformer, it can still be overloaded quickly when
using it for control equipment like zone valves or zone
circulators. Table 7 shows the transformer usage for the
GeoSource DualTEK heat pumps.
Table 7 - Transformer
If the system's external controls require more than the VA
available for external use from the transformer, an
extemal transformer must be used. You can see t}tat in
Figure 2, the heat pump's internal transformer can easily
power the extemal 24-Yolt system. In contrast, if a
system contains components that have their own power
supply, they must be coupled to the heat pump. This can
be accomplished using an isolation relay which isolates
the external systems power supply from the heat pump's
transformer (e.g. use the external systems independent
power supply to energize the coil of a relay, passing a
signal across the Normally Open contacts from the heat
pump's transformer).
The heat pumprs transformer can generally power simpler
control systems consisting of a few relays or zone valves
(depending, ofcourse, on the VA draw ofthe
components). On more complicated control systems the
transformers capacity is used up very quickly.
GNote: For units operating on 208V electrical service,
the transformer must be switched to the correct lead (see
electrical diagrams - Figures 8 and 9). Units are factory
shipped with the ffansformer set for 240V service.
Operating a unit on 208V with the transformer set to
240V will cause the unit to operate with less than normal
control voltage.
B. Thermostat/Aquastat
Consult the instructions ia the thermostat box for proper
mounting and thermostat operaLion.
7
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6
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55 VA
20VA
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Pump Relav
BlowerRelay
Reversine Valve
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Thermostat
Solenoid Valve
Total
Available

I C,q,UffON- miswiring of control voltage on system
controls can result in transformer burnout.
cNote: If a single thermostat controls multiple heat
pumps, the control wiring of the heat pumps must be
isolated from each other. This will prevent the heat
pumps from receiving high voltage through the common
wiring if it is turned off at the circuit breaker for service.
A GeoSource DualTEK heat pump requires at least two
thermostats. The flrst thermostat is a forced air heat
pump thermostat connected to the terminal strip on the
controller. This thermostat controls forced air heating and
cooling as any thermostat would. The second thermostat
is a heating aquastat, which is wired to H and R on the
terminal strip. The aquastat tells the heat pump when
hydronic side water heating is required and when the
hydronic side is satisfied. The heat pump can only run in
one mode at a time, so there is a priority switch on the
controller to regulate mode changes (see Forced
Air/llydronic Priority).
Power is supplied to the thermostat by connecting the R
and X terminals to the heat pump terminal sfip. The G
terminal energizes the blower relay. The Y terminal
energizes the compressor for forced air heating and
cooling.
The unit is put into the cooling mode when the thermostat
energizes the O terminal, which operates the 4-way
reversing valve. The L terminal is used to power a
lockout LED on the thermostat, which indicates a
compressor lockout.
The heat pump's controller regulates compressor
operation when there is an auxiliary heat (W2) or an
emergency heat (E) call from the thermostat. With forced
air priority, a W2 call will energize the elements, along
with the blower and compressor in forced air. With
hydronic priority, if the unit is running in hydronic mode
and receives a W2 call, the blower and electric elements
will energize along with the compressor in hydronic
mode. During emergency heating, the compressor will be
shut down, and not allowed to run.
When a single stage electric heater is used, wire it to the
W2 and X terminals on the left terminal strip on the
controller. Also, wire E and W2 from the thermostat to
the heat pump. This will cause the electric heater to
energize when the thermostat gives an emergency heat or
second stage heat call.
The aquastat closes and passes power to the H terminal,
energizing the compressor and circulation pumps in the
hydronic heating mode. The pump relay is connected to
the circulation pump's 3 pole, high voltage terminal block
(BP). The hydronic side circulation pump receives power
from BP, which is energized by M6. When mounting an
aquastat inside a storage tank, always use a submersible
type aquastat. The aquastat should be installed
approximately 1/3 of the way down into the tank. Set the
aquastat differential to 15nF to avoid short cycling
cNote: The aquastat should be set to give a maximum
leaving water temperature from the heat pump of
115T. This means that the actual setting of the aquastat
will be lower than this (typically 100 to 105T).
Any number or types of thermoslats, aquastats, or
switches can be used with an independent power supply
(typically aZ{-volt transformer) to activate specific zone
controls. These zone controls are normally either zone
pumps (Figure 3) or zone valves (Figure l). End switches
on the zone valves can be used to pass a signal to a pump
relay when the zone valve is open. The pump relay then
activates a common pump, which supplies any number of
zones.
If a thermostat is equipped with an anticipator it should be
set to its maximum setting to avoid interfering with heat
pump operation. The anticipator is a resistor in the
thermostat that heats up as current is drawn through and
satisfies the thermostat prematurely. This reduces system
capacity by restricting run time.
C. Controller
The controller receives a signal from the thermostat and
initiates the correct sequence ofoperations for the heat
pump. The controller performs the following functions:
1) Blower Operation
2) Earth L,oop Pump Initiation
3) CompressorOperation
4) 4-Way Valve Control
5) Compressor Lockouts
6) CompressorAntishort-Cycle
7) System Diagnostics
8) Forced Air/Hydronic Priority
9) Overflow Detection
1. Blower Operation
A signal on the G terminal from the thermostat to the
controller will tell the conroller to energize the blower
The confroller then energizes its M7 output to send
control voltage directly to the blower motor relay.
To change blower speeds, move the wire on the fan
terminal sffip to the desired setting. Changing the speed
from the factory setting can cause problems with output
air temperature or reduced airflow, locking out the unit.
For more information on the blower, including the
optional ECM Variable Speed Blower (-DxVx), see
section III, Duct System/Blower.
2. Earth Loop Pump Initiation
If a PumpPAKrM is used, it should be wired directly to the
contactor of the compressor. If a PumpPAKrM is not
used, a separate pump can be used which is energized
with a pump relay (Note: electrical code will require a
l5

fused disconnect for pumps other than PumpPAKsrM).
When there is a call for an M1 output from the controller,
the contactor will energize, starting the compressor and
earth loop pump.
3. Compressor Operation
A Y signal from the thermostat will tell the controller to
initiate forced air heating or cooling. The controller then
decides, based on lockouts, anti-short-cycle periods, and
priorities, when to bring the compressor on. The Ml
output of the controller energizes the compressor. The
compressor stays on until either the thermostat is
satisfied, the aquastat calls for hydronic heating with
hydronic priority, or a lockout condition occurs.
An H signal from the aquastat will tell the controller to
start in hydronic heating mode. Depending on lockouts,
anti-short-cycle periods and priorities, the controller will
send an Ml signal to start the compressor. The
compressor will stay running in hydronic mode until the
aquastat is satisfied, the thermostat calls for forced air
heating or cooling with forced air priority, or a lockout
condition occurs.
4. 4-Way Valve Control
The conffoller energizes the 4-way reversing valves to
direct the flow of refrigerant. When the unit is running in
forced air cooling, the controller energizes its M3 output
to send control power to fhe cooling reversing valve
(VRl), to switch the refrigerant circuit to the cooling
mode.
When the unit is running in hydronic heating mode, the
controller energizes its M4 output to send control power
to the hydronic reversing valve (VR2), to switch the
refrigerant circuit to the hydronic mode.
5. Compressor Lockouts
A compressor lockout occurs if the high-pressure, low
pressure, or freeze protection pressure switches open.
The controller blocks the signal from the thermostat or
aquastat to the contactor that normally would energize the
compressor. In the event ofa compressor lockout the
controller will send a signal from L on the terminal strip
to an LED on the thermostat to indicate a lockout
condition. On GeoSource DuaITEK units, if the heat
pump locks out in either the forced air or hydronic mode,
the controller will let the other mode run until that mode
also locks out. For example, if a problem with the
hydronic loop causes the heat pump to lock out on one of
the pressure switches, the heat pump will still be able to
run in forced air mode. If the heat pump then locks out
while it is in the forced air mode. the unit will not come
on in either mode.
A lockout condition means that the unit has shut itself
down to protect itself. The unit will have to be shut off at
the circuit breaker for one minute to reset the controller.
Problems that could cause a lockout situation include:
a. Water flow or temperature problems
b. Air flow or temperature problems
c. Internal heat pump operation problems
d. Cold ambient air temperature conditions
tlf a lockout condition exists, the heat pump should not
be reset more than once; a service technician should be
called immediately. 9The cause of the lockout must be
determined. Repeated reset may cause damage to the
system.
6. Compressor Anti-Short-Cycle
An anti-short-cycle is a delay period between the time a
compressor shuts down and when it is allowed to come on
again. This protects the compressor and avoids nuisance
lockout conditions. Anti-short-cycles occur after these
four conditions;
l) A one to two minute time-out period occurs on
the compressor before it will start after its last
shutdown.
2) A four minute 35 second delay is incorporated
into the timing function immediately after power
is applied to the heat pump. This occurs only
after reapplying power to the unit. To avoid this
timeout while servicing the unit, apply power,
disconnect and reapply power very quickly. This
can sometimes eliminate the waiting period.
3) A 30 second to one minute anti-short-cycle will
occur after a low-pressure switch opens in the
cooling mode. This is done to eliminate
nuisance lockout conditions. If the compressor
continuously short cycles in the cooling mode,
shut the thermostat off and call your service
technician.
4) A one to two minute anti-short-cycle occurs
when switching between forced air and hydronic
modes.
7. System Diagnostics
The controller is equipped with diagnostic LED lights
which indicate the system status at any particular time.
The lights indicate the following conditions:
a. 24Yolt system power GREEN
b. Faultorlockout RED
c. Antishort-cycle mode RED
d. Forced Air Compressor operation RED
e. Hydronic Compressor operation RED
f. Pressure switch status on lockout YELLOW
g. controller outputs (Ml thru M10) RED
h. Condensate overflow (optional) RED
8. Forced Air/Ilydronic Priority
Dip Switch #1 on the controller decides forced airl
hydronic priority. When the dip switch is in the ON
position (factory preset), the forced air mode has priority
over hydronic mode. This means that if the heat pump is
running in the hydronic mode, and the thermostat gives a
16

call for forced air, the heat pump will shut down for an
anti-short-cycle period, and then run in the forced air
mode until the thermostat is satisfied. At that time, if the
aquastat is still calling for hydronic heating, the heat
pump will start again in the hydronic mode after an anti-
short-cycle.
If Dip Switch #1 is set to the OFF position, hydronic
heating has the priority over forced air heating or cooling,
9. Over{Iow Detection
An optional overflow detection sensor may be added to
the GeoSource DualTEK heat pumps. This sensor is
located in the drain pan, and monitors the amount of
water accumulated in the pan. If the condensate drain
becomes clogged or kinked, and the unit is not draining
water, the sensor will shut the heat pump off in forced air
cooling for an anti-short-cycle period ofapproximately 3
minutes and 35 seconds. After this time, the heat pump
will start again if the condensate has drained. ff the water
is still present, the unit will go through anti-short-cycles
until the condensate has drained. This protection switch
keeps the condensate from overflowing the drain pan and
possibly leaking onto the floor or ceiling.
XT. STARTUP
Before applying power to the heat pump, check the
following items:
- Water supply plumbing to the heat pump is
completed and operating. Manually open the water
valve on well systems to check flow. Make sure all
valves are open and air has been purged from a loop
system. Never operate the system without correct
water supply.
- All construction dust has been cleaned up and all
sheet-rocking is completed. Construction dust,
especially sheet-rock dust, can plug the air coil and
block airflow. Make sure the filter is clean before
starting the unit.
- Low voltage wiring of the thermostat and any
additional control wiring is complete. Set
thermostat to the *OFF'position.
- All high voltage wiring is correct including fuses,
breakers, and wire sizes.
- The heat pump is located in a warm area (above
45iF). Starting the system with low ambient
temperature conditions is more difficult; do not
leave the area until the space is brought up to
operating temperatures.
- Hydronic side water temperatures are warrn enough
(50oF or above) to start in the heating mode.
- The hydronic side water flow rate is correct (shown
in Table 5). Low water temperature starting may
require flow reduction until the system is up to
operating temperature.
You may now apply power to the unit. A 4 minute 35
second delay on power up is programmed into the heat
pump before the compressor will operate. During this
time the pump relay will energize the hydronic side-
circulating pump, if the aquastat is calling for heat.
Verify that the flow rate and temperature of the hydronic
side flow are at the recommended levels. Also, during
this time, you can verify airflow with the following
procedure:
- Place the thermostat in the "pdlq g}.{rt position. The
blower should start immediately. Check airflow at
the registers to make sure that they are open and that
air is being distributed throughout the house. When
airflow has been checked, move the thermostat to the
"FAN AUTO" position. The blower should stop.
The following steps will assure that your system is
heating and cooling properly. After the initial time-out
period is completed, the red ASC indicator light on the
controller will shut off. The heat pump is now ready for
operation.
- Turn the thermostat up to its highest temperature
setting. Place the thermostat to the "HEAT"
position. The blower will start. The compressor
should start I to 2 seconds later. Ifan electronic
thermostat is used it may cause its own compressor
delay at this time, but the compressor will come on
after the time-out period.
- After the unit has run for 5 minutes, check the return
and supply air temperatures. An air temperature rise
of 25T to 35oF is normal in the heating mode, but
variations in water temperature and water flow rate
can cause variations outside the normal range.
- Turn the thermostat to the "OFF" position. The
compressor and blower will shut down in I to 2
seconds.
- Next, turn the thermostat down to its lowest setting.
Place the thermostat in the "COOL" position. The
blower will start. The compressor will start after an
anti-short-cycle period from its last shutdown. The
anti-short-cycle period is indicated by the red light
on the confroller.
- After the unit has run for 5 minutes, check the return
and supply air temperatures. An air temperature
drop of 15"F to 20"F is normal in the cooling mode
but factors mentioned in the heating section can also
effect temperature drop.
- Set the thermostat to the OFF position, and set the
aquastat to heat at its highest setting.
- After an anti-short-cycle period, the compressor will
come on.
- After the unit has run in the hydronic mode for 5
minutes, check the hydronic side return and supply
water temperatures. A water temperature rise of
10nF to 15nF is normal, but variations in entering
water temperatures and water flow rates can cause
variations.
- Set the thermostat for normal operation.
- Instruct the owner on correct operation ofthe
thermostat, aquastat, and heat pump system. The
unit is now operational.
77

The heat pump is equipped with both high and low
pressure switches that shut the unit offifthe refrigerant
pressure exceeds 400 psi or goes below 25 psi. Ifthe
system exceeds 400 psi, the high-pressure switch will trip
and lock the unit off until power has been disconnected at
the circuit breaker for approximately one minute. System
pressures below 25 psi in the heating mode will trip the
low pressure switch and lock the unit out until the power
- supply has been de-energized for one minute. On a well
water system, the fr eeze protection switch (fi eld ins talled
part number 7 5-1028) will activate the lockout at 35 psi in
the heating mode to protect the water coil against freeze
rupture. After resetting a lockout (by disconnecting
power to the unit) verify that water flow is at the
recommended levels before energizing the compressor.
DO NOT reset a well water system without verifying
water flow. DO NOT reset the system more than once.
9Repeated resetting of the lockout can cause serious
damage if the reason for lockout is not corrected.
I - If lockout occurs more than once contact vour
ECONAR dealer immediatelv. t
XII. SERVICE
Regular service to a GeoSource DualTEK heat pump is
very limited. The biggest factor is changing the air filter.
Other factors could include water coil maintenance on an
open loop system (this maintenance is discussed in
section VI). Setting up regular service checkups with
your ECONAR dealer could be considered. Any major
problems with the heat pump system operation will be
indicated on the thermostat lockout lisht.
A. Filter
The GeoSource DualTEK heat pump is equipped with a
disposable air filter. This hlter should normally be
replaced once a month during normal usage. During
extreme usage or if system performance has decreased,
the filter should be replaced more often.
A dirty fi1ter will reduce the airflow to the system. This
decrease in airflow will reduce the efficiency and comfort
level of the system. In the heating mode, reduced airflow
may increase the cost of operation and, in extreme cases,
cause system lockout due to high refrigerant pressures. In
the cooling mode, reduced airflow may reduce cooling
capacity and in extreme cases ice the aircoil over, causing
system shutdown due to low refrigerant pressures.
If another filter is used in place of the factory specified
filter, it should also be cleaned or replaced in a timely
manner. Be careful in selecting optional filters so that
excessive external resistance to airflow is not induced.
B. Lockout Lights
A lockout light on (he thermostat will light to indicate
major system problems. If lockout occurs, follow the
procedure below:
18
1) Check for a clean filter and correct water supply from
the earth loop or well water system.
2) Reset the system by disconnecting power at the
circuit breaker for one minute, and then reapplying
power.
3) If shutdown reoccurs, check the indicator lights on
the controller in the unit and review the lockout
troubleshooting guide in section XIV of this manual.
4) tlf lockouts persist, call your ECONAR dealer. Do
not continuously reset the lockout condition or
damage may occur.
C. Preseason Inspection
Before each season, the air coil, drain pan, and condensate
drain should be inspected and cleaned as follows:
- Tumoffcircuitbreakers.
- Remove access panels.
- Clean air coil by vacuuming it with a soft-brush
attachment.
- Remove any foreign matter from the drain pan.
- Flush pan and drain tube with clear water.
- Replace access panels and retum power to the unit.
X[I.THERMOSTAT
OPERATION
This section covers basic operation of the standard 2-heat
l-cool thermostat that ECONAR carries. This thermostat
is ECONAR part number 70-2002, Honeywell part
number T8511G. If your thermostat is a different style,
please refer to the instructions supplied with that
thermostat.
The settings of the thermostat are controlled with the
"System", "Fart", "i", up key, and down key buttons. The
System and Fan buttons are located behind the flip-down
panel.
By pressing the "System" button, you can control the
mode that the thermostat operates in. The five system
settings are:
1. Em. Heat - Controls backup heating. In this mode,
the heat pump's compressor is locked out, and only
the backup heating elements (if installed) operate.
2. Heat - Controls normal heating operation.
3. Off - Both heating and cooling are off.
4. Cool - Controls normal cooling operation.
5. Auto - The thermostat automatically changes
between heating and cooling operation, depending
on the indoor temperature.
Note: When the thermostat is set to Auto, there must be
at least a 2oF difference between the Heating setpoint
temperature and the Cooling setpoint temperafure.
The "Fan" button controls the operation of the heat
pump's blower. The Fan button has two settings:
1. On - The blower operates continuously.