A.O. Smith PHPT-60 How to use

RESIDENTIAL HYBRID ELECTRIC HEAT PUMP WATER HEATER
Service Handbook
PRINTED IN THE U.S.A. 0511 321547-000
SERVICE SHOULD ONLY BE PERFORMED BY A QUALIFIED SERVICE TECHNICIAN
®
FOR MODELS:
PHPT-60 (60 GAL.)
PHPT-80 (80 GAL.)
INSTALLATION CONSIDERATIONS -
PREVENTIVE MAINTENANCE -
OPERATION & SERVICE - TROUBLESHOOTING

2
Introduction............................................................................................................................................................ 3
Certification and Approvals.................................................................................................................................... 3
Tools Required....................................................................................................................................................... 3
Terms, Definitions, and Formulas.......................................................................................................................... 4
Safety Precautions ................................................................................................................................................ 5
Installation Check List............................................................................................................................................ 6
Potential Issues ..................................................................................................................................................... 7
Dry Fire Protection / Powered Anode Operation ................................................................................................... 8
Water Piping System ............................................................................................................................................ 9
T&P Valve / Thermal Expansion .......................................................................................................................... 10
General Service / Preventive Maintenance ..........................................................................................................11
Operational Overview.......................................................................................................................................... 12
Operating Your Heat Pump.................................................................................................................................. 13
Control Board Overview ...................................................................................................................................... 14
Control Board Section “A”.................................................................................................................................... 15
Control Board Section “B”.................................................................................................................................... 16
Control Board Section “C” ................................................................................................................................... 17
Control Board Section “D” ................................................................................................................................... 18
Wiring Diagrams............................................................................................................................................. 19-20
Accessing Maintenance Display.......................................................................................................................... 21
Element Test (Continuity Check) ......................................................................................................................... 22
Element Test (Ohm’s Check)............................................................................................................................... 23
Heating Element Replacement............................................................................................................................ 24
Energy Cutout (ECO) Troubleshooting................................................................................................................ 25
Run Capacitor...................................................................................................................................................... 26
Powered Anode Replacement / Removing the Shroud ....................................................................................... 27
Component Check Flowcharts ....................................................................................................................... 28-31
Temperature Sensors .......................................................................................................................................... 32
Resistance vs. Temperature Charts .................................................................................................................... 33
R-134a Temperature Chart.................................................................................................................................. 34
Cleaning the Evaporator...................................................................................................................................... 35
Common Service Problems............................................................................................................................ 36-38
Fault Code Troubleshooting Guide................................................................................................................. 39-44
Draining and Filling the Water Heater ................................................................................................................. 45
Condensate Pump............................................................................................................................................... 46
Parts List.............................................................................................................................................................. 47
Table of Contents

3
Introduction:
Your safety, and the safety of others, is extremely important in the servicing of this water heater. Many safety-related
messages and instructions have been provided in this handbook and on your water heater to warn you and others
of potential hazards. Read, understand and obey all safety messages and instructions that appear throughout this
handbook and in the Installation Instructions and Use & Care Guide that shipped with the water heater. It is very
important that the meaning of each safety message is understood by you and others who service this water heater.
The information contained in this handbook is designed to answer commonly faced situations encountered in
the operation of the residential electric heat pump product line and is not meant to be all-inclusive. If you are
experiencing a problem not covered in this handbook, please contact the Technical Information Center listed on the
back cover of this handbook for further assistance. Additional information is also available on the web site listed on
the back cover of this handbook.
This handbook is intended for use by qualified service technicians and reference should be made to the Installation
Instructions and Use & Care Guide accompanying the product. This handbook contains supplemental information to
the Installation Instructions and Use & Care Guide.
When servicing residential electric heat pump water heaters, it is essential that you return the unit to a safe
condition before you leave the site. All original components must be re-installed and all safety measures must be
implemented. In addition, the recommended water temperature setting is 120°F.
Certifications and Approvals:
Code Compliance - All models meet or exceed federal minimum energy standards effective January 20, 2004,
according to latest editions of the National Appliance Energy Conservation Act (NAECA). They also comply with
the latest editions of the B.O.C.A. National Codes, C.E.C., U.B.C., S.B.C.C., C.A.B.O. and the H.U.D. standards.
All models U.L. listed according to safety specifications outlined in Underwriters Laboratories, Inc. Standards for
Safety (UL 174 and UL 1995)
Tools for servicing residential electric heat pump water heater models:
• Container (to measure flow rate)
• Continuity checker or electrical multimeter (with alligator leads)
• Funnel (for chlorination or scale-removal treatments)
• Hose (to drain tank)
• Needle nose pliers
• Pipe wrench
• Screw drivers (flat tip and Phillips)
• Nut Drivers - 5/16” & 9/32”
• Socket wrench:
1-1/16 inch socket– 6 point deep well (for anode removal)
1-1/2 inch socket (for element removal)
Appropriate extensions
• Thermometer
• Water pressure gauge
• Flashlight
• Drill
• Amp meter-clamp type
Supplies for servicing residential electric heat pump water heater models:
• Chlorine Bleach (for chlorination procedure, as well as algae/scale removal
from condensate drain pan)
• Cotton swabs (to check for minor leaks)
• Teflon®tape or approved thread sealant
• All Purpose ABS/PVC Cement
• Un-Lime or Mag Erad (for removal of scale)
Service Handbook
Figure 1
Digital multimeter shown.

4
Terms, Definitions and Formulas
First Hour Rating (FHR) is a volume of hot water delivered by a water heater during a 1-hour, Department
Of Energy mandate test procedure. The FHR is given in gallons or liters.
Energy Factor (EF) is an indicator of the combined thermal efficiency and standby efficiency of a water
heater. The higher the Energy Factor, the more efficient the water heater will be.
Recovery rate is the amount of water, expressed in gallons per hour (GPH),heated to a given temperature
rise. Residential water heaters are typically rated at approximately 90°F temperature rise. IE: A standard
electric water heater with one 4.5 kW (kilowatt) electric heating element can produce 20 GPH at an
approximate 90°F rise.
Temperature rise is the increase in the temperature from its coldest “inlet” water temperature to the desired
hot “outlet” setting.
Standby efficiency relates to the ability of the product to retain the stored heat (Btu) while the heating
source is not on. Insulation and other services are used to increase this efficiency.
Water (for all practical purposes) cannot be compressed.
Water expands when it is heated. The volume and pressure of water increases when it is heated in a closed
system. IE: Water heated from 90°F to 140°F in a 40 gallon water heater will expand by approximately one-
half gallon.
Minerals and gases will separate from water as temperature increases.
Amperage (Amps) (1 phase) = Watts divided by Volts (Ohm’s Law)
KW Required = (GPH X 8.25 X Temp. Rise X 1.0) divided by (3413)
Ohms = Volts divided by Amperes (Ohm’s Law)
One killowatt is equal to 1000 watts
One kilowatt is equal to 3,413 BTU
Recovery Rate =(KW X 3413) divided by (Temp. Rise X 8.25)
Rise (°F) = (KW X 3413) divided by (GPH X 8.25)
Supply electrical fusing and wiring or breakers should be sized at least 125% of expected heater
amperage, per NEC and local codes.
Water weighs 8.25 pounds per gallon at 120°F
% of Hot water = (Mixed temp. - Cold) divided by (Hot temp. - Cold). This formula gives the number of
gallons drawn from the water heater for each gallon delivered at a shower head or faucet. If the shower head
flow rate (gallons per minute) is known, the draw efficiency and gallon capacity of the water heater may be
used to calculate the length of the showering period in minutes.
Watt Density = the density of the wattage output of the element compared to the surface area of the
element (i.e. “High Watt Density Element” will have the most wattage per square inch of element surface.

5
Safety Precautions
Explosion Hazard
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WARNING
Excessive Weight Hazard
Use two or more people to move and install
water heater.
Failure to do so can result in back or
other injury.

6
Water Heater Location
• Centrally located with the water piping system.
• The flooring beneath the water heater must be able
to support the weight of the water heater when
filled with water (see Table 1).
TABLE 1: Weight of water heater, full of water
Capacity Weight (lbs)
60 Gallon 760
80 Gallon 967
• Located indoors (such as a basement or garage)
and in a vertical position. Protected from freezing
temperatures.
• Provisions made to protect the area from water
damage. Metal drain pan installed and piped to an
adequate drain.
• Sufficient room to service the water heater.
• Sufficient air for the heat pump to function. The
approximate minimum air requirement is 750
cubic feet of space. For example: this would be
a room approximately 10’X9 1/2’ in size with an 8’
ceiling. NOTE: For optimal efficiency, the following
minimum clearances should be maintained: 3 ft. on
the air inlet side, 6 ft. on the air outlet side and 2 ft.
front and back.
• Unrestricted airflow, the unit cannot be placed into
any type of closet or small enclosure.
• The site location must be free from any corrosive
elements in the atmosphere such as sulfur, fluorine,
and chlorine. These elements are found in aerosol
sprays, detergents, bleaches, cleaning solvents,
air fresheners, paint and varnish removers, and
many other commercial and household products.
In addition, excessive dust and lint may affect the
operation of the unit and require more frequent
cleaning, see “Cleaning/Replacing the Air Filter”
section (p.11).
• Ambient air temperature must be between 45°F
and 109°F (inclusive) in order for the heat pump to
work properly. If the ambient air temperature falls
outside these upper and lower limits the electrical
elements will activate to meet hot water demand.
Water System Piping
• Temperature and pressure relief valve properly
installed with a discharge pipe run to an adequate
drain and protected from freezing.
• All piping properly installed and free of leaks.
• Heater completely filled with water, see “Water
Piping System” section (p.9).
• Closed system pressure buildup precautions
installed, see “Closed System/Thermal Expansion”
section (p.10).
• Mixing valve (when applicable) installed per
manufacturer’s instructions see “Water Piping
System” (p.9).
Condensate Drain Line Installation
• Must be located with access to an adequate drain
or condensate pump.
• Condensate drain lines installed and piped to an
adequate drain or condensate pump.
Electrical Connections
• The water heater requires nominal 240 VAC for
proper operation.
• Wiring size and connections comply with all
applicable codes or in the absence of local or state
codes follow NFPA-70, the National Electrical
Code-current edition.
• Water heater and electrical supply are properly
grounded.
• Wiring enclosed in approved conduit (if required by
local codes).
• Dedicated circuit with proper overload fuse or
circuit breaker protection installed.
Post Installation Review
• To maintain optimal operation check, remove and
clean the air filter see “Cleaning/Replacing the Air
Filter” section (p.11).
• Understand the importance of routine inspection/
maintenance of the condensate drain pan and
lines, see “Inspection/Cleaning of the Condensate
Drain Pan & Condensate Drain Lines” (p.46). This
is to help prevent any possible drain line blockage
resulting in the condensate drain pan overflowing.
IMPORTANT: Water coming from the plastic
shroud is an indicator that both condensation drain
lines may be blocked. Immediate action is required.
• Understand how to use the User Interface Module
to set the various modes and functions, see
“Adjusting the User Interface Module/Operating
Modes” (p.12-13).
• Understand the various Operating Modes and
which mode may be best based on season,
ambient temperature, and usage see “Operating
Mode Description” (p.12-13). NOTE: It may be
necessary to temporaily change modes if, for
example, filling a spa or hot tub.
• The Installation Instructions and Use & Care Guide
should be kept with the water heater for reference.
Installation Checklist

7
Potential Installation Issues
Symptom Cause Solution
Temperature set to 60 ºF and not
adjustable
Vacation mode is on Turn off Vacation mode by pressing
the Vacation button
Electric mode selected but the
heat pump is running
Upon initial start up, the heat
pump will run until the tank
temperature reaches the set
point; this is done so that the
heat pump operation can be
verified. The water heater
will operate according to the
selected mode after this first
run.
No action is necessary.
If after heat pump operation has
been verified and element heating
is desired, lower the set point
temperature to 95ºF. The heat
pump will shut off when the tank
temperature is ≥95º F. Set the
temperature to the desired set point.
The elements will now be used for
heating in Hybrid and Electric modes.
Power is applied to the unit, but
there is no display on the User
Interface Module (UIM)
The unit is in Standby; the
power button on the UIM is
RED
Press the power button; it should turn
green and the display should light
up. If the power button does not turn
green, remove the protective film
over the face of the UIM and re-try
the power button.
If the unit does not power up, cycle
power to the unit and re-try using a
thumb.
“Low Water Level Alarm” message
displayed on the UIM
The tank is not completely
filled with water
Purge air from the tank using the
procedure outlined in the “Dry Fire
Element Protection” section (p.8).
If the tank is properly filled, the unit
should operate normally.
“Heat Pump Fault” message
displayed on the UIM
There are 12 potential causes
for this fault
Refer to the Trouble Shooting section
for corrective actions (p.39-44)
Efficiency mode selected but
elements come on instead of heat
pump
Ambient air or water
temperature outside the heat
pump safe operating envelope
Heat pump safety lock out occurs if :
• ambient air temperature is
below 45º F or above 109º F;
• tank temperature is below 59º F

8
Dry Fire is a term used to describe a heating element
that is on and not fully submerged in water. This will
result in permanent damage to the element. The
dry fire element protection algorithm is installed on
this heat pump water heater and prevents damage
to the heating elements in the event that power is
applied to the water heater without sufficient water
in the tank to cover the elements. This routine
takes approximately four (4) minutes. If it is
determined that the element is not fully submersed in
water, an error will be displayed on the user interface:
LOW WATER LEVEL ALARM. The water heater will
not operate while this fault is active and it must be
cleared before the water heater will operate. In order to
clear the error, shut off power to the water heater, and
purge all air from the water heater tank. This is done
by opening all hot water taps in the building. Run the
water until there is no air coming out with the water.
Shut off all hot water taps. Apply power to the water
heater. After four (4) minutes, dry fire detection should
be complete, the error should be cleared and the water
heater should operate normally. If the LOW WATER
LEVEL ALARM repeats, purge air from tank again by
following the method outlined above.
Dry Fire Element Protection
Checking the Powered Anode for Proper
Operation:
When dissimilar metals are in contact with water, a
galvanic cell will likely result and corrosion of the metal
components will occur. If left unchecked, corrosion
will weaken the wall of a water heater tank which will
eventually leak. Passive anodes are typically used to
counteract this corrosion and extend tank life. Passive
anodes erode over time and become less effective
until they stop working all together, another type of
protective device is a powered anode.
A powered anode is an active device that counteracts
galvanic corrosion in the water heater tank. Unlike
a standard depleting anode, a powered anode does
not lose effectiveness over time. The powered anode
circuit is made up of an electronic control, a titanium
anode rod, and the water heater tank. The electronic
control monitors conditions in the tank and produces
a voltage that will prevent galvanic corrosion from
occurring. The titanium anode rod consists of two
functional parts: A steel body which threads into the
tank providing mechanical and electrical connection to
the tank and a titanium rod that is electrically insulated
from the body. The voltage produced by the powered
anode circuit is delivered to the titanium anode rod by
a red wire connected to the tab that connects to the
anode rod. Current flows from the titanium anode rod,
through the water and to the grounded tank wall. The
powered anode circuitry will maintain the minimum
voltage required to protect the tank steel.
Fault detection is built into the powered anode
software. If a fault is detected, an error message
will be displayed on the User Interface Module
(UIM): “Powered Anode Fault”. By checking the
fault code history, see “Accessing the Maintenance
Display” (p.21), a specific fault code can be read to
aid in isolating the cause. Refer to the “Fault Code
Troubleshooting Guide” (p39-44) for the list of powered
anode fault messages, what the messages indicate,
possible causes, and corrective actions.
IMPORTANT: The anode protecting the tank requires
power to the unit to operate. Do not shut off power to
the unit for an extended period of time. If power must
be turned off, drain the tank completely to minimize
corrosion.
Powered Anode Operation

9
Water Piping System
Cold Water
Inlet Valve
Cold Water
Inlet
Pressure Reducing Valve (PRV)
should be installed where the water
supply enters the residence.
In a closed system, use a
thermal expansion tank.
See “Closed System/
Thermal Expansion”
section.
Cold Water Outlet
Shut-off Valve
(Cold)
Tempered Water to Fixtures
Untempered Water Outlet
Vacuum Relief Valve
Mixing Valve - Follow the Mixing Valve’s
Manufacturer’s Installation Instructions.
(Set to 120° F)
6” Maximum
Air Gap
Metal Drain Pan 2 1/2”
Depth Maximum and
2 Inches wider than
the water heater.
Discharge Pipe
(Do Not Cap or Plug)
Temperature and
Pressure Relief Valve
Union
Shut-off Valve (Hot)
Drain Line 3/4”
ID Minimum Drain
Condensate Drain Lines*
Massachusetts: Install a vacuum relief in
cold water line per section 19 MGL 142.
* If an adequate drain is not available for the condensate drain lines then a condensate pump should be used. DO NOT discharge the condensate drain
lines into the metal drain pan.
Union
Hot
(Outlet)
Cold
(Inlet)
Figure 2
Piping, fittings, and valves should be installed according to
the installation drawing (Figure 2). If the indoor installation
area is subject to freezing temperatures, the water piping
must be properly insulated.
Water supply pressure should be 50-60 PSIG (.35 MPa)
and not exceed the maximum 80 PSIG (.55 MPa). If
the supply line pressure exceeds 80 PSIG (.55 MPa),
a pressure reducing valve (PRV) with a bypass should
be installed in the cold water supply line. This should
be placed on the supply to the entire house in order to
maintain equal hot and cold water pressures.
IMPORTANT:
• Heat must not be applied to the water fittings on
the heater as they may contain nonmetallic parts. If
solder connections are used, solder the pipe to the
adapter before attaching the adapter to the hot and
cold water fittings.
• Always use a good grade of joint compound and be
certain that all fittings are tight.
IMPORTANT: DO NOT over apply joint compound.
Piping Installation
1. Install the water piping and fittings as shown (Figure 2).
Connect the cold water supply (3/4” NPT) to the fitting
marked “Cold”. Connect the hot water supply (3/4”
NPT) to the fitting marked “Hot”.
2. The installation of unions in both the hot and cold
water supply lines are recommended for ease of
removing the water heater for service or replacement.
3. Some local codes may require, and the manufacturer of
this water heater recommends, installing a mixing valve
or an anti-scald device in the domestic hot water line as
shown (Figure 2), or at the point of use. These valves
reduce the point-of-use temperature of the hot water
by mixing cold and hot water and are readily available.
Contact a licensed plumber or the local plumbing
authority for more information.
4. Some local codes may require, and the manufacturer
of this water heater recommends, installing a pressure
reducing valve (PRV) in the cold water inlet line where
it enters the residence as shown (Figure 2).
5. If installing the water heater in a closed water system,
install an expansion tank in the cold water line as
specified under “Closed System/Thermal Expansion”
(p.10).
6. Install a shut off valve in the cold water inlet line. It
should be located close to the water heater and be
easily accessible. Know the location of this valve and
how to shut off the water to the heater.
7. Install a discharge line from the temperature and
pressure relief valve in the opening marked “T & P
RELIEF VALVE”. See Figure 3 and the “Temperature
and Pressure Relief Valve” (p.10)
8. After piping has been properly connected to the water
heater, open the nearest hot water faucet. Then open
the cold water shut off valve and allow the tank to
completely fill with water. To purge the lines of any
excess air and sediment, keep the hot water faucet
open for three (3) minutes after a constant flow of water
is obtained. Close the faucet and check all connections
for leaks.

10
tubing so that any discharge from the valve exits only within
6 in. (152mm) above drain, or at any distance below, the
structural floor, and does not contact any live electrical part.
The discharge opening must not be blocked or reduced in
size under any circumstance.
IMPORTANT: Only a new temperature and pressure relief
valve should be used with your water heater. Do not use an
old or existing valve as it may be damaged or not adequate
for the working pressure of the new water heater. Do
not place any valve between the relief valve and the
tank.
The Temperature & Pressure Relief Valve:
• Shall not be in contact with any electrical part.
• Shall be connected to an adequate discharge line.
• Shall not be rated higher than the working pres-
sure shown on the data plate of the water heater.
The Discharge Line:
• Shall not be smaller than the pipe size of the relief
valve or have any reducing coupling installed in the
discharge line.
• Shall not be capped, blocked, plugged or contain
any valve between the relief valve and the end of
the discharge line.
• Shall terminate a maximum of 6 in. (152mm) above
a floor drain or external to the building. In cold
climates, it is recommended that the discharge pipe
be terminated at an adequate drain inside the build-
ing.
• Shall be of material listed for hot water distribution.
• Shall be installed to allow complete drainage of
both the valve and discharge line.
Explosion Hazard
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6” (152mm)
Maximum
Air Gap
Drain Pan
2 1/2” (63.5mm)
Depth Maximum and
2” (51mm) wider than
the water heater.
Discharge Pipe
(Do Not Plug or Cap)
Temperature and
Pressure Relief Valve
Drain Line 3/4” (19mm)
ID Minimum Drain
Figure 3
Temperature and Pressure
Relief Valve Installation
For protection against excessive pressures and
temperatures, a temperature and pressure relief valve must
be installed in the opening marked “T & P RELIEF VALVE”
(Figure 3).
To reduce the risk of excessive pressures and temperatures
in this water heater, install temperature and pressure relief
protective equipment required by local codes, but no less
than a combination temperature and pressure relief valve
certified by a nationally recognized testing laboratory that
maintains periodic inspection of the production of listed
equipment or materials, as meeting the requirements for
Relief Valves and Automatic Shutoff Devices for Hot Water
Supply Systems, ANSI Z21.22 - latest edition. This valve must
be marked with the maximum set pressure not to exceed
the marked maximum working pressure of the water heater.
Install the valve into an opening provided and marked for
this purpose in the water heater, and orient it or provide
Temperature and Pressure Relief Valve
Closed System/Thermal Expansion
As water is heated, it expands (thermal expansion). In
a closed system, the volume of water will grow. As the
volume of water grows, there will be a corresponding
increase in water pressure due to thermal expansion.
Thermal expansion can cause premature tank failure
(leakage). This type of failure is not covered under
the limited warranty. Thermal expansion can also
cause intermittent temperature-pressure relief valve
operation: water discharge from the valve due to
excessive pressure build up. The temperature pressure
relief is not intended for the constant relief of thermal
expansion. This condition is not covered under the
limited warranty.
A properly-sized thermal expansion tank should be
installed on all closed systems to control the harmful
effects of thermal expansion. Contact a plumbing
service agency or your retail supplier reguarding the
installation of a thermal expansion tank.

11
General Service information
• Volts times Amps = Watts
• Watts divided by Volts = Amps
• Replacement Elements:
Use replacement elements that are rated at the
same wattage, voltage and shape indicated on
the heater model and rating plate. Installing an
element with a higher voltage rating or wattage
output may create a safety hazard. (It could
overload the heater wiring, the supply wiring, or the
fusing.) Installing an element with a lower wattage
or voltage rating will reduce performance.
Also, select replacement elements with the most
surface area (low watt density) available for your
water heater. By spreading the heat of the element
over a greater area, the lime (calcium) buildup rate
should be reduced.
Elements constructed of Incoloy are much more
durable than zinc-coated copper elements.
• Element Cycling:
Most two-element water heaters are non-
simultaneous. In other words, only one element
operates at a time.
If the upper element fails, the customer will lose hot
water. (Power switches to the lower element only
after the water at the top of the tank is heated.) If
the lower element or thermostat fails, the customer
should still have hot water in the top 1/3 of the tank.
Also, with two-element water heaters, the lower
element and thermostat will cycle more frequently
than the upper element and thermostat. For this
reason, the lower element will normally accumulate
lime faster and fail more often than the upper
element. This increased cycling also causes
lower thermostats to fail more often than upper
thermostats.
Routine Preventive Maintenance
At least monthly, a visual inspection should be made of the following:
• Air Filter (Remove and inspect, clean if needed, and reinstall).
• Condensate drain pan and condensate lines.
• The lower metal drain pan for standing water which may indicate a clogged condensate drain pan, condensate
lines, or plumbing leak.
• Leaking or damaged water piping.
• Presence of corrosive materials in the installation area.
• Presence of combustible materials near the water heater.
• After servicing this water heater, check to make sure it is working properly, see “Operational Overview/Initial Start
Up” (p.12)
IMPORTANT: If you lack the necessary skills required to properly perform this visual inspection, you should not
proceed, but get help from a qualified person.
Cleaning/Replacing the Air Filter
Air Filter Cleaning/Replacement
IMPORTANT: Before attempting to clean or replace the air filter, press the power button to place the water heater
in Standby Mode and turn-off power to the water heater at the circuit breaker/fuse box.
1. Locate the screw securing the filter panel to the heat pump shroud and remove it.
2. Remove (slide) the filter from the unit.
3. If you are replacing the filter, skip to step 4. To clean the filter, use a vacuum with a hose attachment to
remove any dust or debris.
4. Place the new or cleaned filter into the filter panel and secure the filter to the shroud with the screw loosened
earlier. Use the slots for guides when inserting the filter into the water heater and replace the screws.
5. Restore power to the water heater and press the power button to turn the water heater on.
NOTE: The water heater will conduct a system diagnostic prior to operation.

12
Operational Overview
Heat Pump Water Heater Operation:
Heat pump water heaters remove heat from
surrounding air and use that heat to heat water.
By doing so, heat pump water heaters can operate
much more efficiently and at significantly lower costs
compared to standard electric water heaters.
This heat pump water heater has four (4) operating
modes for maximum flexibility in meeting hot water
needs under a variety of conditions. Available modes
are: Efficiency, Hybrid, Electric and Vacation.
Operating Mode Descriptions:
Efficiency Mode provides the highest efficiency and
lowest cost operation by using only the heat pump to
heat water. Recovery time and efficiency will vary with
ambient temperature and relative humidity. Efficiency
will be greatest when both are high and recovery time
will be shortest. At lower temperatures and relative
humidity levels, efficiency will be lower and recovery
will take longer. Heat pump operation is allowed
from 45°F to 109°F ambient temperature. At ambient
temperatures lower that 45°F and greater than 109°F
the heat pump will not operate. Similarly, if the water
temperature in the tank is less than 59°F, the heat
pump will not operate. The unit will operate in electric
mode until ambient and water temperatures return to
the safe operating range of the heat pump.
Hybrid mode provides the best combination of
energy efficiency and hot water delivery. The heat
pump will be used to heat water after moderate hot
water use. When a large quantity of hot water is used,
the upper electric heating element will heat water in
order to speed up recovery. Once the upper portion of
the tank reaches set point, the element will shut off and
the heat pump will heat water until the average tank
temperature reaches set point. Hybrid mode provides
the highest first hour hot water delivery with excellent
economy.
Electric mode allows operation like a standard
electric water heater, using the upper and lower
heating elements to heat water. The heat pump is not
used in this mode. The key advantage of using this
mode is that it eliminates the cool air exhausted from
the heat pump. During cold weather months, this may
be desirable. Hot water delivery and operating costs
are comparable to a standard electric water heater with
similar tank capacity.
Vacation mode should be used when hot water will
not be needed for a period of time greater than three
(3) days. In vacation mode electric elements are used
to heat water and set point is a non-adjustable 60°F.
Minimal electricity will be used and maintaining 60°F
minimizes the risk of the water heater freezing in cold
weather.
User Interface Module Overview:
The User Interface Module (UIM) is used to control
the heat pump water heater. It displays useful
information about the operating status of the water
heater, the selected mode of operation and the set
point temperature. Fault information will be displayed
should a malfunction occur with one of the components
or sub-systems. The UIM also is used to set the water
heater to the desired set point temperature, mode of
operation, temperature units (°F or °C) and to check
the operating condition of the heat pump through the
maintenance display, see “Accessing the Maintenance
Display”(p. 21).
Initial Start Up:
When powered up for the first time (or when power
is re-applied after a power outage or service work is
performed), the control will run the dry fire check to
establish that the tank is completely filled with water,
see “Dry Fire Element Protection” (p.8). The UIM will
display “Dry Fire” during this operation, which will take
about four (4) minutes. After eight (8) minutes have
elapsed, the fan should come on; after an aditional
thirty (30) seconds, the heat pump compressor should
turn on. Note that during the initial start up, the heat
pump will come on regardless of operation mode
selected. This is intended to allow for evaluation of
the heat pump to ensure that it is operating properly.
The heat pump will heat water until the set point
temperature is reached in the tank; it will then shut
off. After this initial start up is complete, the water
heater will operate per operational mode setting,
ambient air and tank water tamperatures, and set point
temperature.

13
Operating Your Heat Pump Water Heater
°F/°C
LOCK
HEAT PUMP
ELEMENT
EFFICIENCY
F
VACATION
ELECTRIC
HYBRID
EFFICIENCY
Power Button: On - Green
Standby - Red
Temperature
Down (Decrease)
Button
Temperature
Up (Increase)
Button
Operational Mode Buttons
Water
Temperature
Set Point
Water Heater
Mode/Status
Indicator
Water Heater
Efficiency Status
Icon
LCD Display Panel
Lock Button
Fahrenheit/Celsius
Temperature Display
Button
LCD Control
Panel Lock Icon
Heat Pump
Functioning
Icon
Element
Functioning
Icon
Figure 4 User Interface Module (UIM)
Turning the Unit On:
The power button is located at the bottom of the UIM,
below the display. There are two (2) conditions for the
power button indicated by color: RED-the unit is in
STANDBY and power is applied to the unit; GREEN-the
unit is ON. Press the power button to turn the unit on if
needed.
NOTE: All buttons on the User Interface are touch
sensitive and require only a light touch.
Adjusting Set Point Temperature:
The water temperature can be adjusted from 95°F to
150°F. Use the Up and Down Buttons on
the UIM to set the desired temperature.
IMPORTANT: Before attempting to adjust the
thermostat, read the information on water temperature
adjustment above. If the instructions are not clear,
contact a qualified person.
IMPORTANT: Filling a spa or hot tub from this water
heater may result in extended recovery/re-heat time.
Switching (temporarily) to Hybrid Mode or Electric
Mode will decrease the recovery/re-heat time. Be sure
to switch back to the desired operational mode when
finished. The factory temperature set point is 120°F.
Notify homeowner if the set point is increased above
120° at any time for any reason. Return the set point to
a safe level upon completion of service work.
Selecting Operating Mode:
The operating mode can be changed by touching
the desired mode icon on the User Interface Module
(Figure 4).
NOTE: While vacation mode is on, the other modes
cannot be selected and set point temperature can not
be changed. Turn off vacation mode by pressing the
vacation mode button. Desired mode and set point can
now be selected.
EFFICIENCY
Efficiency Mode - Is the most energy efficient
mode. This mode uses the heat pump to heat
water in the tank. The elements are not used
unless the ambient operating temperature is
below 45°F or above 109°F.
HYBRID
Hybrid Mode - Combines high energy efficiency
with reduced recovery time. This mode uses
the heat pump as the primary heating source.
The heating element will heat water if demand
exceeds a predetermined level so that the
set point temperature can be recovered more
quickly.
Electric Mode - The water heater functions as
a conventional electric unit, relying totally on
the elements to heat the water in the tank. This
mode may be useful in winter to eliminate the
output of cold air from the unit.
VACATION
Vacation Mode - The set point changes to 60°F
which is the temperature that will be
maintained. This mode is recommended for
periods of three (3) days or more in which the
water heater will be idle. Vacation Mode
minimizes energy consumption and minimizes
the risk of freezing during cold weather.
NOTE: To activate Vacation Mode touch the
Vacation Mode button. To deactivate Vacation
Mode, touch the Vacation Mode button again.
Other Controls
Lock - Holding this button for more than 3
seconds switches the lock mode on or off.
When the User Interface Module is locked a
symbol and “Lock” text will be visible on the
display and there will be no access to mode
change or set point change.
°F/°C
°F/°C - The button switches the display to
show the set temperature in Fahrenheit or
Celsius.
ELECTRIC

14
A
B
C
D
Figure 5
Control Board Overview
Heat Pump Water Heater Control Board Overview:
The Control Board on the Heat Pump Water Heater monitors the complete heating system and reports any
errors through the User Interface Module (UIM). Based on the inputs from the sensors and/or the manual
inputs from the UIM, the Control Board determines which heating mode the unit should be in to reach the user
set-point.
Above, the Control Board is broken down into four (4) sections. The specifics of each section are explained in
greater detail in the following pages.

15
FUS202FUS201
CN207
CN201
Figure 6
CN202 CN206
Section “A”
CN 201 Line Power:
• Pin 1 - Control board power wire L1 (240VAC)
• Pin 2 - Control board power wire L2 (240VAC)
• Pin 3 - Not used
• Pin 4 - Control board power wire ground
CN 202 ECO Bottom:
• Pin 1 - Connect to lower heating element
• Pin 2 - Connect to L1 behind ECO switch
CN 206 Compressor:
• Pin 1 - Compressor power L1
• Pin 2 - Unused
• Pin 3 - Unused
• Pin 4 - Compressor power L2
CN 207 Fan Low/high:
• Pin 1 - Fan power L1
• Pin 2 - Unused
• Pin 3 - Fan power
FUS 201:
• Fuse 201 (3 Amp, 250V, slow blow) fuses the L1 power leg coming to the Control Board
FUS 202:
• Fuse 202 (3 Amp, 250V, slow blow) fuses the L2 power leg coming to the Control Board
Section “A” of Control Board

16
RY 203 Upper Element Relay:
• Terminal 1 - COM Connects to L1 behind the ECO Switch.
• Terminal 2 - NO Connects to the upper heating element.
CN 203 Powered Anode:
• Pin 1 - Powered anode signal
• Pin 2 - Ground
Figure 7
Terminal 1
Terminal 2
Pin 2
Pin 1
Section “B”
Section “B” of Control Board

17
Section “C” of Control Board
CN 204 Upper and Lower tank water temperature sensors:
• Pin 1 - Upper water temperature sensor on tank.
• Pin 2 - Upper water temperature sensor on tank.
• Pin 3 - Lower water temperature sensor on tank.
• Pin 4 - Lower water temperature sensor on tank.
CN 212 Temperature Sensors:
• Pin 1 - Ambient temperature sensor.
• Pin 2 - Ambient temperature sensor.
• Pin 3 - Discharge temperature sensor.
• Pin 4 - Discharge temperature sensor.
• Pin 5 - Coil temperature sensor.
• Pin 6 - Coil temperature sensor.
Figure 8
CN 204
CN 212
CN 211/215
CN 208
Dip Switch
Section “C”

18
CN 211/215 UIM Communication Cable:
• Pin 1 - +5 V
• Pin 2 - +12 V
• Pin 3 - Signal A+
• Pin 4 - Signal B+
• Pin 5 - Ground
Note: Both CN211 and CN215 are identical and either can be used for the UIM communication.
CN 208 Overload Detection:
• Pin 1 - High pressure switch.
• Pin 2 - High pressure switch.
• Pin 3 - Low pressure switch.
• Pin 4 - Low pressure switch.
• Pin 5 - Not used
• Pin 6 - Not used
• Pin 7 - Not used
• Pin 8 - Not used
• Pin 9 - Condensate pump signal overflow (optional)
• Pin 10 - Condensate pump signal overflow (optional)
Note: Pin 9 and 10 are connected by a jumper wire. This wire should be cut and wired in series to
the overflow switch of the field supplied condensation pump (optional).
SW 201 Dip Switch:
• SW 1 - Not used
• SW 2 - Not used
• SW 3 - Not used
• SW 4 - Not used
Led 201 Power Indicator:
• LED 201 when illuminated, indicate that 5 and 12 Volts DC are present for the UIM
Section D
LED 202/203 Powered Anode Indicators:
• LED 202-
One (1) flash/second (approx.), indicates
there is power to the anode circuit.
• LED 203-
Two (2) flashes/second (approx.), indicates
proper operation.
Four (4) flashes/second (approx.),
indicates a fault.
Figure 9
LED
203 / 202
Section D
Section “C” of Control Board (con’t)

19
Wiring Diagram for Models With Relay
L1
L2
Red
Black
Approved Connectors
Junction Box
Overload
Protectio
To 240v
1 Phase
Power supply
Electrical
Service ground
Circui
Breaker
Ground
Wire
Green
nt
C
R
S
G
COMPRESSOR
1
10
15
15
1
6
1
412
1
4
1
2
1
3
1
4
N.O.
COM.
CN201
CN207
CN202
CN206
RY 203
CN208
CN215
CN211 CN212
CN204 CN203
HEAT PUMP WATER
HEATER CONTROLLER
COIL TEMP. SENSOR
DISCHARGE TEMP. SENSOR
AMBIENT TEMP. SENSOR
LOW PRESSURE
SWITCH
HIGH PRESSURE
SWITCH
TANK UPPERTEMP. SENSOR
TANK LOWER TEMP. SENSOR
A-A
C-C
D-D ANODE - POWERED
LOWER ELEMENT
2KW
13
4
HIGH LIMIT
SWITCH
JUNCTION
BOX
TANK
L1 L2
ANODE-POWERED
GROUNDING
STRIP
G
TANK JACKET
24
10RELAY
68
CAPACITOR
BLOWER
D-D
C-C
L1
L2
G
TANK UPPER
TEMP. SENSOR
TANK LOWER
TEMP. SENSOR
B-B
A-A
B-B
OVERFLOW
SWITCH
HEAT PUMP WATER
HEATER WIRING DIAGRAM
b
a
AC 240V 60Hz 1PH.
LOWER
ELEMENT
BLOWER
POWER
LINE
UPPER
ELEMENT
OVERLOAD DETECTION
ANODE-POWERED
HP TEMP.
TANK
TEMP.
COMPRESSOR
DISPLAY
USER INTERFACE
UPPERELEMENT
4.5 KW
NOTES
1. THEFUNCTIONOF CN211 AND CN215 IS THE SAME, EITHER CN211 OR
CN215 SHOULD BE CONNECTED TO COMPUTER BY SPECIAL CONNECTOR.
2. IF ANY OF THE ORIGINAL WIRE AS SUPPLIED MUST BE REPLACED,
USE THE SAME SIZE ONLY TYPE 105°C THERMOPLASTIC OR EQUIVALENT..
3. TANK LOWER ELEMENT MUST NOT EXCEED 2KW.
GREEN
RED
RED
RED
GREEN
GREEN
GREEN
GREEN
GREEN GREEN AND YELLOW COMBINATION
GREEN
GREEN
RED
BLACK
RED
BLACK
WHITE
BLACK
BLACK
BLACK
BLACK BLACK
WHITE
WHITE
RED
RED
RED
BLACK
BLACK
BLACK
RED
RED
BLACK
RED
BLACK
RED
BLACK WHITE
WHITE
BLACK
RED
FIELD INSTALLED
FACTORY INSTALLED
GR
GREEN
RED
BLUE
BLACK
WHITE
WHITE
BLUE
BROWN
RED
BLACK
BLACK
BLACK
BLACK
OPTIONAL OVERFLOW SWITCH,
NORMALLYCLOSED
RESERVED UIM CONNECTION
a
b
2
WHITE
WHITE
WHITE
Figure 10
Figure 10a
Capacitor
Compressor Control Relay
Compressor control relays were used in early production models so the compressor’s operating voltage did
not have to travel through the tank’s high limit switch (Figure 10a).

20
Wiring Diagram for Non-Relay Models
L1
L2
Red
Black
Approved Connectors
Junction Box
Overload
Protectio
To 240v
1 Phase
Power supply
Electrical
Service ground
Circui
Breaker
Ground
Wire
Green
nt
FIigure 11