Vortex combo-pac User manual

CP-1605
Installation Instructions
combo-pacTM
hot water air handler
with high efficiency EC motor and
iStat6 Control
45 Cowansview d.
Cambridge, Ontario
N1 7L2
Phone: [phone]
Fax: [phone]
[email protected]
www.vortexsource.com

CP-1605

CP-1605
Table of Contents
TYPICAL PLUMBING CONNECTIONS .......................................................................................................... 5
ELECT ICAL WI ING DIAG AM .................................................................................................................. 7
INT ODUCTION ............................................................................................................................................ 10
HOW IT WO KS ........................................................................................................................................... 11
COOLING.......................................................................................................................................................... 11
HEATING .......................................................................................................................................................... 11
CONTINUOUS FAN ............................................................................................................................................ 11
P ODUCT DESC IPTION ............................................................................................................................ 11
CABINET .......................................................................................................................................................... 11
HEATING COILS ................................................................................................................................................ 12
FAN AND MOTO .............................................................................................................................................. 12
CI CULATING PUMP .......................................................................................................................................... 12
CHECK VALVE .................................................................................................................................................. 12
CONNECTING TO A WATE HEATE ................................................................................................................... 12
CONNECTING TO A BOILE ................................................................................................................................ 12
EQUIPMENT SELECTION AND SIZING ...................................................................................................... 13
HEAT LOSS ...................................................................................................................................................... 13
AI HANDLE SELECTION ................................................................................................................................. 13
DUCT LAYOUT .................................................................................................................................................. 13
PLUMBING LAYOUT ........................................................................................................................................... 14
INSTALLATION ............................................................................................................................................. 14
AI HANDLE MOUNTING .................................................................................................................................. 15
DUCTWO K ...................................................................................................................................................... 15
ISK OF FEEZING ........................................................................................................................................... 16
ELECT ICAL ................................................................................................................................................ 16
THE MOSTAT ................................................................................................................................................... 16
A/C CONDENSING UNIT .................................................................................................................................... 17
STA T-UP P OCEDU ES........................................................................................................................... 17
SE VICE AND MAINTENANCE ................................................................................................................... 19
T OUBLESHOOTING ................................................................................................................................... 20
EFE TO THE CONT OLS MANUAL AS WELL. ..................................................................................................... 20
THE MOSTAT CALL EO ............................................................................................................................... 20
PUMP DOES NOT UN ........................................................................................................................................ 20
PUMP IS NOISY AT STA T-UP ............................................................................................................................. 20
WATE HEATE T&P IS WEEPING ...................................................................................................................... 20
INSUFFICIENT O NO HEAT ................................................................................................................................ 20
COLD WATE AT HOT FAUCET ............................................................................................................................ 21
FAN UNS FO COOLING BUT NOT HEATING ........................................................................................................ 21
HEATING DU ING STANDBY MODE ..................................................................................................................... 21
combo-pac AI HANDLE PA TS & ACCESSO Y LIST ........................................................................ 22
P ODUCT WA ANTY ............................................................................................................................... 23

CP-1605
Important notes For the Installer

A Quick Check List
 Are the water connections to the water heater oriented in a way to
avoid trapping air in the heating circuit? (see diagram on next page)
 Is the purge valve installed on the return line from the air handler
upstream from the isolation valve?

Is the air handler hung and isolated to avoid transmitting vibration
through framing and duct work? Or is the air handler on a
housekeeping pad?
 Are the isolation valves full-port? estrictive valves will limit
performance.
 Are Thermostat connections correct, including cooling and continuous
run connections?
 Have the packing materials been removed from the blower and the
pump ?
 Is there an installation manual for the home owner ?
 Is the unit accessible? Are there clearances for service and component
replacement?

Are the supply plenum and return duct/drop acoustically lined ? (at
least 6ft. of the return duct/drop and the supply plenum are
recommended)
 Is the filter cover in place? Is a clean filter in place? Is the supplied
filter rack installed?

CP-1605
TYPICAL PLUMBING CONNECTIONS

CP-1605

CP-1605
ELECT ICAL WI ING DIAG AM
Motor choke required for 3/4hp only

CP-1605
Physical Properties
Cabinet dimensions Supply air eturn air water
inlet Shipping
Model Type A
depth
B
width
C
height
d x e f x g and
outlet Weight
CP30 20” 14” 24” 12”x16” 14”x18” 1/2” 80 lb.
CP63, CP70,
CP80 22” 25” 31.5” 20”x20” 18”x23” 3/4” 110 lb.
CP100 22” 25” 53.5” 20”x20” 18”x23” 1” 120 lb.
Unit Specifications: combo-pac ECTM air handlers
MODEL: CP30-EC CP63-EC CP70-EC CP80-EC CP100-EC
*Heating Capacity (Btu/h) 120F water 21,000 45,000 51,000 59,000 76,000
*Heating Capacity (Btu/h) 130F water 28,000 58,000 65,000 73,000 91,000
*Heating Capacity (Btu/h) 140F water 30,000 63,000 70,000 80,000 106,000
*Heating Capacity (Btu/h) 160F water 37,000 80,000 90,000 103,000 135,000
*Heating Capacity (Btu/h) 180F water 48,000 99,000 110,000 125,000 164,000
(USGPM) Heating 3.0 4.8 4.8 4.8 7.0
Maximum Heating Airflow (CFM) 800 1200 1400 1800 2000
Max. External Static Pressure (“wc)** 1.2 0.6 1.1 0.7 1.0
Max. Cooling Capacity (Tons) 2.0 3.0 3.5 5.0 5.0
Blower Motor Full Load (Amps) 5.5 5.5 7.7 9.6 9.6
Circulator Full Load (Amps) 0.6 0.8 0.8 0.8 0.8
* Based on 70F return air and high fan speed. Contact Vortex for performance at lower water
temperatures.
** Air handler can deliver maximum programmed airflow at any static pressure below this value.

CP-1605
Unit Specifications: combo-pacTM air handlers with small-D TM
MODEL CP30 CP30 CP63 CP63 CP70 CP70 CP80 CP80 CP100 CP100
Number of 4”
outlets1 5 7 8 10 9 12 12 17 15 20
Cooling Capacity
(Tons) 1.5 2.0 2.0 2.5 2.5 3.5 4.0 5.0 4.0 5.0
Heating Capacity
(MBH) 130F water3 24 28 48 58 56 65 66 73 77 91
Heating Capacity
(MBH) 140F water3 26 30 51 63 60 70 73 80 90 106
Heating Capacity
(MBH) 160F water3 32 37 65 81 76 90 94 103 115 135
Heating Capacity
(MBH) 180F water3 41 48 81 100 93 110 114 125 139 164
(USGPM) Heating 3.0 3.0 4.8 4.8 4.8 4.8 4.8 4.8 7.0 7.0
Max. Heating
Airflow2 600 800 900 1200
1050 1400 1350 1800 1350 1800
Max. ESP (in.WC) 2
2.3 0.9 1.5 0.6 1.8 1.1 1.8 0.7 1.8 0.6
Blower Motor Full
Load (Amps) 5.5 5.5 5.5 5.5 7.7 7.7 9.6 9.6 9.6 9.6
Circulator Full
Load (Amps) 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8
1. Minimum number of outlets required at rated airflow. efer to SmallD Design for options.
2. These are example air flows and ESP based on number of outlets and programmed
heating/cooling speed. Higher ESPs are available at lower airflows. Contact Vortex for
performance at lower speeds.
3. Based on 70F return air. Contact Vortex for performance at lower water temperatures.

CP-1605
INT ODUCTION
combo-pac ™ air handlers are state-of-
the-art units designed for use with
hydronic (boiler) systems or in
combination space and water heating
systems (Combo Systems). Two key
features include automatic heating
capacity adjustment and automatic
cooling dehumidification adjustment.
The programmable control allows for
customization and adjustment of air
speeds and capacity. Combo heating
systems use the home’s water heater to
provide both the space heating and
domestic hot water, eliminating the need
for a furnace.
Combo heating systems are ideally
suited for single-family homes,
townhouses and apartments where the
cost of a furnace does not make sense or
space requirements are limited. They
are also great for additions, renovation
and finished basements as a
replacement for, or in addition to the
existing heating system. Vortex air
handlers are also great for hydronic
heating systems using ground-source
heat pumps. They are the smallest units
available in their capacity range.
combo-pac ™ air handlers are designed
to take the guesswork out of system
sizing and installation. Matched
specifically to common water heater
sizes, Vortex air handlers can be quickly
sized using the quick sizing information
in our spec sheets or from air handler
performance curves. For applications
requiring special consideration, call
888-781-8151 for answers to questions
related to sizing, installation or trouble-
shooting for any of Vortex air handlers.
Vortex provides you with the quietest
operating air handler available. By using
large capacity, high output heating coils,
these air handlers deliver more heating
per volume of air, which means warmer
delivered air temperatures.
combo-pac™ air handlers are intended
for conventional and small-D™ duct
systems with higher operating static
pressure. efer to the small-D™ design
manual for more details on duct design
and installation.

CP-1605
HOW IT WO KS
The key to the combo-pac ™ system is
the level of comfort provided by the
unique control system. The features
described are adjustable by the installer.
efer to the control instructions for
details.
Cooling
In automatic mode, a call for cooling will
adjust fan speed according to the
measured humidity. During periods of
high humidity, the fan will slow down and
more humidity is removed from the air.
During drier conditions, the fan runs
faster and removes less humidity.
Measurements and adjustments are
made continuously.
Fixed fan speed is a programmable
option.
There is also an adjustable pre-cooling
and post-cooling feature to reduce fan
speed for improved efficiency and
comfort.
Heating
In automatic mode, the fan will run at a
low level. If the thermostat is not
satisfied within 15 minutes (adjustable),
the fan will speed up every minute until
the thermostat is satisfied or the fan
reaches full speed. The controller
“learns”, so that for the next heating call,
the fan will speed up if the last heating
call was too long or the fan will slow
down if the last heating call was too
short.
Fixed fan speed is a programmable
option.
There is also an adjustable pre-heating
and post-heating feature to reduce fan
speed for improved efficiency and
comfort.
Continuous Fan
When the thermostat fan switch is set to
continuous fan, the fan will run at the
programmed speed (default is 50% of
maximum). When there is a call for
heating or cooling, the normal heating or
cooling speed will over-ride the
continuous fan setting. Once the
thermostat is satisfied, continuous fan
speed will resume.
P ODUCT DESC IPTION
Cabinet
All cabinets have a tough, durable low
maintenance pre-painted finish.
Cabinet dimensions are designed to
provide maximum installation flexibility.
efer to installation requirements for
more details.

CP-1605
Heating Coils
All heating coils are potable water grade
copper suitable for use in plumbing
systems. No lead solder is used in any
component construction. All coils and
internal piping conform to ASTM B68 or
ASTM B88 standards.
High-density aluminum fins provide
maximum heat transfer for small coil
surface.
Fan and Motor
All fans are wide body dynamically
balanced for extra quiet operation.
Multi-directional sleeve bearing motors
allow mounting in any direction for
maximum installation flexibility.
Circulating Pump
The circulating pump is matched for
maximum performance. Air handlers
come with internally mounted pumps for
ease of installation. Air handlers can be
special ordered with external, field
installed pumps, when it is desirable to
locate the circulator below the air
handler, such as in attic installations.
Check Valve
Check valves serve two purposes:
• protect against back-flow of water to
avoid short circuiting around the
water heater during domestic water
use.
• protect against thermal siphoning.
Thermal siphoning is flow of water
through the space heating circuit while
the circulating pump is not operating due
to hot water rising by natural convection.
During summer months this will cause
overheating, interfere with air
conditioning and waste energy.
All air systems come supplied with spring
loaded, vertical lift check valves. These
check-valves have been tested and
proven to resist thermal siphoning for
installations where the air handler
elevation does not exceed the distance
above the water heater shown in the
table below.
Check Valves
valve size
Maximum
elevation
1/2”(12mm) 25 feet(8 metres)
3/4”(20mm) 50 feet(15 metres)
Connecting to a Water Heater
Any properly sized gas, propane or oil
fired water heater will work in a combo
heating system. Make sure the water
heater being used is approved for combo
applications. (Most manufacturers’
heaters are approved.) Tank-less water
heaters may reduce the capacity of air
handlers due to the higher internal
pressure drop. (Call Vortex for details)
Connecting to a Boiler
All air handlers are compatible for use
with boilers. Standard drawings are
available from Vortex for most boiler
applications.

CP-1605
EQUIPMENT SELECTION AND SIZING
Proper sizing of system components is
crucial for proper operation.
Steps for sizing and selection:
1) Obtain room by room heat loss and/or
heat gain
2) Determine heating water temperature
3) Select air handler from specification
sheet
5) Determine duct layout
Heat Loss
Make sure a proper room-by-room heat
loss and heat gain for the dwelling is
calculated using H AI, ASH AE or other
approved sizing method.
Air Handler Selection
Select the desired air system that will
meet 100%-140% of the heating load
and 80%-120% of the cooling load.
If using a boiler system, select a boiler
that has an output that meets or exceeds
the heat loss of the space being heated.
If the boiler is meeting additional loads,
size the boiler to meet the total combined
load.
For combo heating systems, use an
approved sizing method such as the
Unified Combo Guidelines published by
H AI. In areas where the UCG or a local
sizing code is not applicable, use the
following method for sizing combo
systems:
1) Select an air handler that meets or
exceeds the calculated heat loss at the
water heater operating temperature
(130F/55C or 140F/60C).
2) Select a water heater with an output
that is at least 120% of the heat loss
uct Layout
Make sure a proper duct design has
been completed for the dwelling using
H AI, ASH AE or other approved
design method.
Supply air Plenum
Provide a supply air plenum that is the
same dimensions as the outlet flanges of
the air handler. A length of 36 inches is
recommended. Acoustic lining is
recommended.
A smooth, square-to-round transition
may be used in place of the supply air
plenum for horizontal installations where
there is only one supply main.
For vertical applications where the air
conditioning coil is installed in the supply
air plenum, the cooling coil must be
supported at least 4 inches (100mm)
above the heating coil face on brackets
or channel to ensure unimpeded airflow
through the heating coil.
Plenum takeoffs may be mounted on the
end of the plenum or the sides of the
plenum, but not both. Spin-in collars or
transition takeoffs may be used, but not
both.
Supply mains
Plan duct layout to avoid branch runs in
outside walls or attics and to minimize
the length of the main duct

CP-1605
Where practical, provide parallel main
ducts to various floors or zones rather
than running a single larger duct with
tees. For applications with 3 or more
floors or any application where a large
seasonal adjustment in airflow is
anticipated, provide parallel supplies with
volume dampers accessible for seasonal
adjustments. For example; a 4-storey
townhouse will probably require vastly
different airflow rates for the upper floors
between cooling and heating seasons. If
there are two main supply trunks, the
supply trunk serving the upper 2 floors
can be damped down in the heating
season to better balance the air flows.
Supply mains may be round duct or
equivalent rectangular duct.
ound duct can be spiral duct, welded or
snap lock seams.
ectangular duct must be at least 26
gauge for all dimensions. The aspect
ratio for square ducts (wide dimension
over short dimension) shall not exceed
2.5 to1.
eturn air duct
The return air duct should be sized for a
total pressure drop of not more than
0.15”w.c. Using conventional sizing
methods and installed in accordance with
H AI guidelines or equal. It is
recommended that the return air duct or
drop be acoustically insulated for at least
6 feet nearest the air handler. For noise
attenuation, at least 2 changes in
direction over the total return air duct
system is recommended.
efer to the small-D™ design guide for
additional requirements for small
diameter/higher static duct applications.
Plumbing Layout
efer to the plumbing diagrams as a
guideline.
Any suitable hydronic pipe is acceptable
for use with the air handler. Do not
exceed 150 psi or 180F (82C). The
boiler, piping or other components may
have more restrictive ratings. If
connecting to a water heater, all
plumbing and components must meet
local plumbing code requirements.
Size piping to match air handler sizing.
Increase one pipe size if distance from
boiler or water exceeds 25ft. or size pipe
according to an accepted design method.
For boiler systems, include expansion
tank, pressure relief valve, pressure
gauge and a suitable fill system. Some
of these may be included in the boiler.
Include drains at system low points and
manual air vents at high points as
required. A temperature gauge near the
inlet to the air handler inlet is
recommended but not required.
15psi is the minimum recommended
design pressure for proper pump
operation. Higher pressure may be
necessary for systems of significant
elevation e.g. basement to attic.
INSTALLATION

CP-1605
The installer must adhere strictly to all
local and national code requirements
pertaining to the installation of this
equipment.
Detailed instructions are shipped with all
accessory items and should be followed
in detail.
Air Handler Mounting
The air handler can be installed in any
direction. Its compact dimensions even
allows for installation between joists. The
air handler can be floor mounted or hung
from straps. Some precautions must be
observed for some of the possible
mounting positions.
For installations where the access door
faces up or down, select an air handler
with an external pump to avoid the pump
being mounted with its shaft vertical. The
pump shaft must be mounted horizontally
to avoid premature failure.
The air handler can be hung by securing
straps through any of the existing screw
holes in the cabinet. When the existing
screw is too short for securing a
mounting strap, a longer screw can be
used provided care is taken not to
damage any internal components.
When fastening straps using screws
other than those supplied with the
cabinet, special care should be taken in
the vicinity of the coil to avoid tube
puncture.
Warning!: Do not put screws into the
cabinet directly in front of and behind
the coil.
3/4” screws can be safely installed on
either side of the coil.
The cabinet is designed so that the
return air can be located on either side of
the cabinet, through the bottom of the
cabinet, or from the back. Position the
filter rack so that the filter is readily
accessible.
Install the air handler with the door firmly
screwed in place to make sure the
cabinet remains square.
Provide at least 2 feet (0.75 metres) of
service clearance in front of the access
panel of the air handler. Zero clearance
is acceptable on all other faces.
For vertical installations with a cased
cooling coil on the return, install air
handler on a minimum 2” (50mm)
housekeeping pad to allow room for
minimum 2” trap in the condensate drain.
This trap is necessary to prevent air
leakage through the drain. efer to the
cased cooling coil installation manual for
more details.
uctwork
General
Ductwork installed in unheated spaces
such as attics must be installed between
the insulation and the heated space.
Provide at least -12 of insulation above
ducts. If cooling is required, the branch
and trunk lines must be insulated and
sealed with a vapour barrier prior to
applying house insulation.
If a fresh air duct is required, make
connection to return air plenum at least 6
feet (2m) upstream from filter. Insulate all
fresh air ducts.
Supply Ductwork

CP-1605
Supply trunks may be square or round.
SEAL all joints and seams with metal
tape or sealing compound. Volume
dampers for each of the main supply
trunks must be accessible for balancing.
(Near the supply plenum is preferred)
Locate outlets at least 6 inches (150mm)
from outside walls or window coverings.
eturn Ductwork
eturn air plenum should be the same
cross sectional area as the air handler
return air opening. In vertical
installations, a conventional return air
drop and elbow is acceptable. It is
recommended that the return duct /drop
be acoustically lined for 6 feet (2m)
nearest the air handler.
Risk of Freezing
Steps must be taken to prevent the hot
water coil from freezing. Coils that have
failed due to freezing and damage
caused by frozen coils are not covered
under warranty.
H V and Fresh air connections
Fresh air and H V connections to
ductwork can pose a risk of dumping cold
air into ductwork during periods of stand-
by or continuous run. Calculate mixed
air stream temperatures and provide
interlock controls to prevent freezing
conditions.
Evaporator coils
Evaporator cooling coils that are
mounted above the hot water coil pose a
risk to the hot water coil in the event that
the compressor contactor on the
condenser sticks in the on position.
When the call for cooling is satisfied, the
blower will stop running and allow cold
air from the evaporator coil to fall onto
the hot water coil.
Attic and crawl spaces
Air handlers may be located in areas
subject to freezing conditions. It is
necessary to protect the hot water coil
and condensate drain from freezing.
Condensate traps should be installed in
the heated space. Give consideration to
insulating the air handler or installing it
into a small, insulated mechanical room.
Consideration can also be given to an
isolating heat exchanger and anti-freeze.
ELECT ICAL
Warning! - Make sure unit is properly
grounded. Locate air handler on a
separate electric circuit, or use the same
circuit as the water heater or boiler where
permitted.
Air handler wiring diagrams are located
on the blower or door for easy reference
during installation and servicing.
Nameplate data is located on the side of
the unit.
All air handlers operate on
115VAC/1ph/60hz line voltage. All
control circuits are 24 VAC. One leg of
the 24 VAC is grounded to the chassis.
Thermostat

CP-1605
combo-pac ™ air handlers are
compatible with most standard heat/cool,
heat pump, “electric heat”, “gas heat”,
set-back or electronic thermostat. Some
electronic thermostats (primarily “power
robbing” types) require the addition of a
resistor between the W & C terminals
and the Y & C terminals. This is usually
covered in the thermostat instruction
manual. A 1,000 ohm, 5 watt resistor on
each of the W and Y terminals will
usually be enough to drain the current
required to power the thermostat. Some
thermostats will need 250 ohm, 10 watt
resistors on each of the W and Y
terminals. For two-stage thermostats,
contact Vortex.
Heat Anticipator Setting
For optimum comfort the anticipator
setting should be set to provide
approximately 4 cycles per hour
Typical Heat
Anticipator Setting
0.25 amps
Thermostat wire from the thermostat is
connected to screw terminals located
inside the air handler. The thermostat
should be connected as follows:
– power (24vac)
W – heating
Y– cooling (if present)
G – continuous run fan
C -- ground
Connect the thermostat to the
appropriate screw terminal.
.
Boiler
The screw terminals labeled TT are dry
contacts for connection to a boiler or
external pump. The contacts are rated
for up to 240vac max. and 10Amps. Max.
A/C Condensing Unit
Connect to Y1 and COM on the screw
terminal. For two-stage condensers, use
Y2 for second stage.
STA T-UP P OCEDU ES
Do not start the air handler or water
heater until ALL air has been purged!
1.Fill the boiler loop or water heater with
water, but do not start it.
2.Purge all air from the boiler heating or
domestic water system.
3.Purge all air from the space-heating
loop by closing the isolation valve on the
return leg of the loop and open the drain
to purge air. Open the return leg isolation
valve and then close the drain valve.
4.Start the boiler or water heater
according to the manufacturer’s
instructions. Set the design water
temperature and wait for the system to
shut off. You can check that the water
heater is set properly by running hot
water from a faucet into a glass. Using a
thermometer measure the temperature of
the water as soon as the water heater
burner shuts off. If the set-point
temperature is too low or is above 140F,
reset the tank control, run water until the
burner starts again and repeat the
measurement.
5.Turn on the power to the air handler
and set the room thermostat for heat to
energize the fan and pump. If a gurgling
sound is present, it should subside within
one minute. If noise is still present after

CP-1605
one minute, repeat step 3 to purge air as
necessary.
6.Check pipes for heating to make sure
there is flow.

CP-1605
SE VICE AND MAINTENANCE
Filter
The air handler is provided with a high-
efficiency, pleated filter. This filter should
be inspected monthly and replaced as
required. eplacement filters are
available from Vortex.
Duct cleaning
If proper filter maintenance is adhered to,
duct cleaning will not be required for the
life of the equipment.
Coils
Air conditioning and heating coils should
not require cleaning if the filter
maintenance schedule is adhered to. If a
filter is damaged or collapses from
plugging, dust may foul the coils. If this
happens, replace the filter and carefully
vacuum the heating coil. The fan may
need to be removed by a service
technician to gain access to the face of
the heating coil.
Air conditioning coil
At the start of each cooling season,
check the drain connection to the cooling
coil to ensure it is free of debris. If a
plugged air conditioning coil is
suspected, call a service technician for
testing and cleaning
Fan and motor
Check fan for dust once a year. If dirty,
vacuum to remove dust. Keeping the fan
blades clean will reduce noise and
improve the capacity and efficiency of the
heating system
Pump
The circulating pump is water lubricated
and should require no regular
maintenance. The system control may
have an optional cycle timer to exercise
the pump even during prolonged periods
of no heat to avoid seizing from long idle
periods.

CP-1605
T OUBLESHOOTING
Refer to the controls manual as well.
Thermostat Call Error
First, review “How It Works” on page 11
for normal operation. It is normal for the
fan to change speeds in heating mode.
Disconnect all thermostat wires at the air
handler and test one at a time with a
jumper between and G then W then Y.
If the air handler works properly, the
issue is in the thermostat or thermostat
wire.
If there is a call for cooling and call for
heating at the same time, the heating call
will have priority and the air conditioning
condenser (outdoor unit) will come on.
Check the thermostat for correct wiring.
Some electronic thermostats and power
robbing thermostats apply a voltage to
the W and/or Y and/or G terminal. With
the thermostat off, the voltage at W, Y
and G should be zero compared to
ground (C). Excessive voltage will be
interpreted as a call from the thermostat.
Pump does not run
In areas where hard water is present the
pump may “stick” and fail to run. Often,
closing the isolation valve on the return
leg and opening the drain port so that
water flows through the pump can free
this. If it fails to free the pump, removal
for cleaning or replacement is necessary.
The daily pump exerciser will help
prevent pump sticking.
Pump is noisy at start-up
Air is present in heating loop. If sound
has not diminished within 1 minute,
purge air in accordance with the Start-Up
procedures. If heat source is a water
heater, check to make sure branch
connections for heating loop are
horizontal to prevent the collecting of air
in the heating loop. See the drawing:
Typical Plumbing Connections at the
front of this manual.
Water heater T&P is weeping
A check valve or back-flow preventer
may have been installed in the system.
Some form of pressure relief may be
required. Options are:
• Install expansion tank
• Install pressure relief valve; locate
outlet over laundry tub or floor
drain.
• Install combination toilet
tank/pressure relief valve
Insufficient or no heat
• Plugged air filter or coil. efer to
Maintenance section for filter care
and coil cleaning.
• Air in heating loop; purge system.
• Inlet and outlet connections to air
handler backwards; reverse
connections.
• Water heater supply tube (dip
tube) is restricted or damaged;
check and/or replace.