American Water Heater 50 Gallon Residential Hybrid Electric Heat Pump Water Heater HPSE10250H045DV user manual

							11
OPERATING YOUR WATER HEATER
Before Using
1.  Make sure the water heater has been properly    installed. See “Installing Your Water Heater”  section.
2.  Make sure the air filter is correctly seated, as it may shift  during shipping or installation. 
NOTICE: Make certain that there are no obstructions on 
top of the unit that may block inlet or exaust air flow. See 
“Repair Parts Illustration” section.
3.  Completely fill the tank with water (See “Water Piping”  section). 
4.  After the water heater tank is completely filled with water,  connect electrical power to the water heater.
5.  Read the “Water Temperature Regulation” section of this  manual.  If you do not fully understand these instruction, 
contact a quali fi ed 

person. 
6. 

When powered on the unit will start to run a system 
diagnostic. This typically takes eight minutes, (the user 
interface module will display “-”, “--”, “---” repetit\
ively 
during this period). Once complete, proceed to the next 
step. 
NOTE: If the system diagnostic yields any codes, 
reference the Diagnostic Code section in this manual.
7.  Adjust the thermostat to the desired temperature setting as described under “Adjusting the User Interface 
Module/Operational Modes” section.
IMPORTANT: Do not attempt to operate this water heater 
if the unit has been submerged, subjected to  fl ooding, 

or 
surrounding insulation has been exposed to water in any 
way.  
Do not attempt to repair a unit subjected to fl  ood conditions. 
Water heaters subjected to fl  ood conditions or any time the 
unit has been submerged in water require replacement of 
the entire water heater.
Safety Shut-off (ECO)
This water heater is designed to automatically shut-off in the 
event that the water temperature exceeds 190°F / 87.8°C. 
A temperature limit switch or ECO (Energy Cut Off) is used 
to shut off the power to the system if the water temperature 
exceeds 190°F / 87.8°C (See “Water Temperature 
Regulation” section). To reset the ECO disconnect power at 
the circuit breaker/fuse box then remove the upper access 
panel. Reset the ECO by fi  rmly pushing in the red reset 
button located on the ECO block. If the ECO continues 
to shut-off the water heater, contact a qualifi  ed person for 
service.
Water Temperature Regulation
Water temperature over 125°F can cause 
severe burns instantly or death from scalds.
Children, disabled and elderly are at highest
 risk of being scalded.
Feel water before bathing or showering.
Temperature limiting valves are available.
WARNING
The water heater is adjusted to a temperature setting of 
no higher than 120°F / 48.8°C when it is shipped from the 
factory. Water temperature can be regulated by adjusting 
the User Interface Module to the preferred setting as shown 
in “Adjusting the User Interface Module/Operational Mode” 
The preferred starting point is 120°F / 48.8°C. There is a 
hot water scald potential if the temperature set point is set 
too high. 
IMPORTANT:  Adjusting the set point above 120°F / 48.8°
 C 
on the User Interface Module  will increase the risk of scald 
injury in the times shown below.  
Table 2
Water 
Temperature 
°F/°C Time for 1st 
Degree Burn 
(Less Severe Burns) T

ime for 
Permanent Burns 
2nd & 3rd Degree  (Most Severe Burns)
110°/43.3°
116°/46.6°
116°/46.6° 122°/50°
131°/55°
140°/60°
149°/65°
154°/67.7° (normal shower temp.)
(pain threshold) 35 minutes1 minute
5 seconds
2 seconds 1 second
instantaneous 45 minutes
5 minutes
25 seconds 5 seconds
2 seconds
1 seconds
(U.S. Government Memorandum, C.P.S.C., Peter L. Armstrong, Sept. 15,1978)
NOTE: During low demand periods when hot water is not 
being used, a lower temperature set point will reduce energy 
losses and may satisfy your normal hot water needs. If hot 
water use is expected to be more than normal, a higher 
temperature set point may be required to meet the increased 
demand. 
When leaving your home for extended periods (vacations, 
etc.) set the water heater to Vacation Mode. See “Adjusting the 
User Interface Module/Operational Modes” section.  This will 
maintain the water at low temperatures with minimum energy 
losses and prevent the tank from freezing during cold weather. 
NOTE: When returning from an extended stay remember to 
set the water heater back to the desired Operational Mode. 
						

							12
Adjusting the User Interface Module/Operational Modes
Water Temperature Adjustment
The water temperature can be adjusted from 95°F / 35°C to 
140°F / 60°C. Use the Up and Down Buttons  
 
on the front panel to set the desired temperature. The 
setting temperature will blink on the display, press Mode/
Enter button to confi  rm.
The water temperature can be adjusted quickly by pressing 
the “Temperature Up” button and holding for three seconds.
IMPORTANT: Before attempting to adjust the thermostat, 
read the “W

ater Temperature Regulation” section. If the 
instructions are not clear, contact a quali fi ed person. 
IMPORTANT: For increased water demand, 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  fi nished.
Operating Mode Descriptions
The operating modes can be changed sequentially by 
pressing the Mode/Enter button (Figure 12). The Operation 
Mode Indication Light will turn on when the relevant mode 
is selected. 
This unit is equipped with technology that senses the 
amount of water drawn from the unit. While in Ef fi ciency or 
Hybrid mode, during normal usage, the unit will operate the 
heat pump for maximum ef fi ciency. In times that the water 
usage is above normal, this unit has the ability to use one 
element (upper or lower) and the heat pump simultaneously 
to help improve recovery. This transition is seamless and 
will go unnoticed.
◊  Efficiency Mode - Provides the highest efficiency and  lowest cost operation by using only the heat pump for 
heating. Recovery time and efficiency will vary with 
ambient temperature and relative humidity. Efficiency 
will be greatest, and recovery quickest, when both 
are high. At lower temperatures and relative humidity 
levels, efficiency will be lower and recovery will take 
longer. Heat pump operation is allowed from 45°F / 
7.2°C ambient temperature. At ambient temperatures 
lower than 45°F / 7.2°C and greater than 120°F / 
48.8°C, the heat pump will not operate. Similarly, if 
the water temperature in the tank is less than 59°F 
/ 15°C, 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 - This is the default, recommended 
setting, combining 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 on only the 
elements for heat. This mode may be useful in winter 
to eliminate the output of cold air from the unit.
◊  Vacation Mode - The controller adjusts the water  temperature to approximately 60°F. This mode 
is recommended when the water heater is not in 
use for a long period of time, to minimize energy 
consumption and prevent the water heater from 
freezing during cold conditions. 
NOTE: When Vacation Mode is selected, the 
vacation timer will be displayed. Press the Up and 
Down button to modify the timer to desired number 
of vacation days (setting range: 1 to 99 days). The 
vacation timer will blink on the display; press the 
Mode/Enter button to confirm the vacation timer. To 
deactivate Vacation Mode, press the Mode/Enter 
button to switch to the desired mode.
IMPORTANT: Do not shut off power to the unit for 
extended periods of time. If power must be turned 
off for an extended period of time, drain the tank 
completely.
CAUTION: Hydrogen gas is produced in a hot water 
system served by a heater that has not been used for a 
long period of time (2 weeks or more).  Hydrogen gas is 
extremely fl  

ammable. To reduce the risk of injury under 
these conditions, it is recommended that the hot water 
faucet be opened for several minutes at the kitchen 
sink before using any electrical appliance connected to 
the hot water system. When hydrogen is present, there 
will probably be an unusual sound such as air escaping 
through the pipe as the water begins to  fl ow. There 
should be no smoking or open  fl ame near the faucet at 
the time it is open. 
						

							13
Operational Conditions
Water Odor
In each water heater there is installed at least one anode 
rod (see parts sections) for corrosion protection of the tank. 
Certain water conditions will cause a reaction with this rod 
and the water
. The most common complaint associated 
with the anode rod is one of a rotton egg smell in the 
hot water. This odor is derived from hydrogen sulfide gas 
disolved in the water. The smell is the result of four factors 
which must all be present for the odor to develop:
A. A concentration of sulfate in the supply water.
B. Little or no dissolved oxygen in the water.
C. A sulfate reducing bacteria which has accumulated 
within the water heater (this harmless bacteria is nontoxic 
to humans).
D. An excess of active hydrogen in the tank. This is caused 
by the corrosion protective action of the anode.
Smelly water may be eliminated or reduced in some 
water heater models by replacing the anode(s) with one 
of less active material, and then chlorinating the water 
heater tank and all hot water lines. Contact the local water 
heater supplier or service agency for further information 
concerning an Anode Replacement Kit and the chlorination 
treatment. If the smelly water persists after the anode 
replacement and chlorination treatment, we recommend 
that chlorination or aeriation of the water supply be 
considered to eliminate the water problem.
Water Heater Sounds
During the normal operation of the water heater, sounds or 
noises may be heard. These noises are common and may 
result from the following:
1.  Normal expansion and contraction of metal parts     during periods of heat-up and cool-down.
2. 

Sediment buildup on or around the elements could 
create varying amounts of noise and may cause  
premature tank failure. Drain and flush the tank as 
directed under the “Draining and Flushing” section.
3.  The heat pump compressor or fan running.
Stacking
Stacking occurs when a series of short hot water draws (3 
gallons or less) are made. This causes increased cycling 
of the heat pump and/or heater elements and can result in 
increased water temperatures at the hot water outlet. An 
anti-scald device is recommended in the hot water supply 
line to reduce the risk of scald injury.
Figure 12
NOTE:  The display will go into “Sleep Mode” for energy 
saving if there is no operation on any button for 15 min-
utes. All the display and light will be turned off except for 
the “Opertional Mode Indication Light”, which will be on 
all the time when the unit is powered on. The unit will be 
awakened by pressing any button.
Other Controls
°F/°C  °F/°C Switch - Press “Temperature Down” button  and hold for 3 seconds to switch temperature unit 
between Farenheit and Celsius
Power Saver Enable/Disable - Press “Mode/Enter” button 
and hold for 3 seconds. The power saver feature will be 
activated and the display will show “P.S.”, and the setting 
temperature alternatively. This feature allows the unit to be 
managed by grid or other utility based load management 
programs.
To deactivate the power saver, press “Mode/Enter” button 
and hold for 3 seconds.
Heat pump defrosting indication - There will be frost accu-
mulating on the evaporator when the heat pump is oper-
ated under low ambient temperatures. The controller will 
order the unit to enter into defrosting cycle to optimize the 
heat pump operation performance. During the defrosting 
period, the user interface module will display “ICE” as an 
indication.
Out of heat pump operation range - The user interface 
module will display “HPO” as an indication that the ambient 
and/or water temperature condition is out of the heat pump 
operation range. 
						

							14ANODE ROD INSPECTION
Each water heater contains at least one anode rod, which 
will slowly deplete (due to electrolysis) prolonging the life 
of the water heater by protecting the glass lined tank from 
corrosion. Adverse water quality, hotter water tempera-
tures, high hot water usage, hydronic heating devices and 
water softening methods can increase the rate of anode 
rod depletion. Once the anode rod is depleted, the tank 
will start to corrode, eventually developing a leak.
Certain water conditions will cause a reaction between the 
anode rod and the water. The most common complaint 
associated with the anode rod is a rotten egg smell pro-
duced from the presence of hydrogen sulfide gas dissolved 
in the water. IMPORTANT: Do not remove the anode rod 
permanently as it will void any warranties. A special anode 
rod may be available if water odor or discoloration occurs.
NOTE: This anode rod may reduce but not eliminate water 
odor problems. The water supply system may require spe-
cial filtration equipment from a water conditioning company 
to sucessfully eliminate all water odor problems.
Artificially softened water is exceedingly corrosive because 
the process substitutes sodium ions for magnesium and 
calcium ions. The use of a water softener may decrease 
the life of the water heater tank.
The anode rod should be inspected after a maximun of 
three years and annually thereafter until the condition of 
the anode rod dictates its replacement. NOTE: Atrificially 
softened water requires the anode rod to be inspected 
annually.
The following are typical (but not all) signs of a depleted 
anode rod (Figure 13):
•  The majority of the diameter is less than 3/8.
•  Significant sections of the support wire (approx, 1/3 or 
more of the anode rods length) are visible.
If the anode rod shows signs of either or both it should be 
replaced.
NOTE: Whether re-installing or replac-
ing the anode rod, check for any leaks 
and immediately correct if found.
In replacing the anode:
1.  Turn off power to the water heater.
2.  Shut off the water supply and open  a nearby hot water faucet to depres-
surize the water tank.
3.  Drain approximately 5 gallons  of water from the tank. (Refer to 
Draining and Flushing for proper 
procedures). Close drain valve.
4.  Remove old anode rod.
5. Use Teflon
® tape or approved pipe 
sealant on threads and install new 
anode rod.
6.  Turn on water supply and open a nearby hot water  faucet to purge air from water system. Check for any 
leaks and immediately correct any if found.
7.  Restart the water heater as directed in this manual.  See the repair part illustration for anode rod location. 
Do not remove the anode leaving the tank unprotected. 
By doing so, all warranty on the water heater tank is 
voided.
AIR IN HOT WATER FAUCETS 
HYDROGEN GAS: Hydrogen gas can be produced in 
a hot water system that has not been used for a long 
period of time (generally two weeks or more). Hydrogen 
gas is extremely fl  ammable and explosive. To prevent the 
possibility of injury under these conditions, we recommend 
the hot water faucet, located farthest away, be opened for 
several minutes before any electrical appliances which 
are connected to the hot water system are used (such 
as a dishwasher or washing machine). If hydrogen gas is 
present, there will probably be an unusual sound similar 
to air escaping through the pipe as the hot water faucet is 
opened. There must be no smoking or open  fl ame near the 
faucet at the time it is open.
HIGH WATER TEMPERATURE SHUT OFF SYSTEM
A non-adjustable high temperature limit control operates 
before steam temperatures are reached. The high limit is in 
the same area as the upper thermostat and must be reset 
manually when it operates. BECAUSE THE HIGH LIMIT 
OPERATES ONLY WHEN ABNORMALLY HIGH WATER 
TEMPERATURES ARE PRESENT, IT IS IMPORTANT 
THAT A QUALIFIED SERVICE AGENT BE CONTACTED 
TO DETERMINE THE REASON FOR OPERATION 
BEFORE RESETTING.
•  Turn off the heater electrical supply. Do not attempt to  reset thermostat with power on.
•  Remove the screw securing the outer door and remove  door.
•  Fold up the insulation to expose the reset button.
•  Reset the high limit by pushing the red button marked  reset.
•  Replace the insulation so that it completely covers the  thermostat and element.
•  Replace the outer door.
•  Turn ON electric power to the water heater.
Figure 13:
tInspection and replacement of anode rod recommended tAvoid water heater damage 
						

							15
MAINTENANCE OF YOUR WATER HEATER
Temperature and Pressure
Relief Valve
Manually operate the temperature and pressure relief valve  
once a year to make sure it is working properly (Figure 14). 
To prevent water 
damage, the valve 
must be properly 
connected to a 
discharge line which 
terminates at an 
adequate drain.
Standing clear of the 
outlet (discharged 
water may be 
hot), slowly lift and 
release the lever 
handle on the 
temperature and 
pressure relief valve to allow the valve to operate freely and 
return to its closed position. If the valve fails to completely 
reset and continues to release water, immediately 
disconnect the electrical power, close the cold water inlet 
valve and call a qualifi ed person. 
Figure 14
T emperature and Pressure 
Relief V  alve 
Manual Relief 
Va  lv e 
Discharge line to drain 
Explosion Hazard
If the temperature and pressure relief valve 
is dripping or leaking, have a qualified 
person replace it.
Examples of a qualified person include:
licensed plumbers, authorized electric 
company personnel, and authorized service 
personnel.
Do not plug valve.
Do not remove valve.
Failure to follow these instructions can 
result in death or explosion.
WARNING
Routine Maintenance
Routine visual inspections should be made of the following:
•  Remove and inspect the air filter, clean if needed, and  reinstall - quarterly.
•  Condensate drain pan and condensate lines - annually.
•  The lower metal drain pan for standing water which may  indicate a clogged condensate drain pan, condensate 
lines, or plumbing leak - annually.
•  Leaking or damaged water piping - annually.
•  Presence of corrosive materials in the installation area -  annually.
•  Presence of combustible materials near the water heater  - annually.
•  After servicing this water heater, check to make sure it  is working properly. (See “Operating Your Water Heater” 
section of this manual.)
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.
Air Filter Maintenance
The heater will monitor the heat pump operation status 
and indicate whether the filter should be cleaned. If the 
User Interface Module displays “SF” code, this indicates 
the filter should be cleaned or replaced with the following 
process (See exploded view of unit on last page for air filter 
location).
IMPORTANT: Before attempting to clean or replace the 
air fi  

lter, turn-off power to the water heater at the circuit 
breaker/fuse box.
1.  Take the two tabs on the air filter and remove (slide) it  from the top cover of the unit.
2. 

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.
3.  Place the new or cleaned filter into the water heater.
4.  Restore power to the water heater and turn the water  heater on. NOTE: the water heater will conduct a 
system diagnostic prior to operation. 
Condensate Drain Maintenance
IMPORTANT: Before attempting to clean or replace the 
condensate drain pan or lines, shut-of f power to the water 
heater at the circuit breaker/fuse box.
1.  Remove the top jacket by loosening the screws securing  it to the unit.
  
2.  Check the condensate drain pan and drain lines for any  dirt or debris that might interfere with proper drainage. 
Wipe out any dirt or debris with a damp cloth.
3.  Once the condensate drain pan and lines have been  inspected/cleaned, secure the top jacket to the water 
heater.
4.  Restore power to the water heater and turn the water  heater on. 
NOTE: The water heater will conduct a system diagnostic 
prior to operation.  
						

							16
ScrewsWires
Element
Figure 15
Screw-in
Element
Figure 16
GasketSpud
Draining and Flushing
It is recommended that the tank be drained and 
fl ushed 
every 6 months to remove sediment which may build up 
during operation. The water heater should be drained if 
being shut down during freezing temperatures. To drain the 
tank, perform the following steps: 
1.  Turn off the power to the water heater at the circuit  breaker/fuse box.
2.  Open a nearby hot water faucet until the water is no  longer hot.
3.  Close the cold water inlet valve.
4.  Connect a hose to the drain valve and terminate it to an  adequate drain or external to the building.
5.  Open the water heater drain valve and allow all of the  water to drain from the tank. Flush the tank with water 
as needed to remove sediment.
6.  Close the drain valve, re fi ll the tank (open the cold 
water inlet valve), and restart the heater as directed in 
this manual. 
IMPORTANT: Do not turn on power to the water heater 
unless it is completely  fi 

lled with water. To ensure that 
the tank is full, open a hot water faucet and allow the 
water to run until the air is purged and the water  fl ows 
uninterrupted from the faucet.  
NOTE: 

The water heater will conduct a system 
diagnostic prior to operation.  
If the water heater is going to be shut down for an extended 
period, the drain valve should be left open. 
Heating Element Replacement
WARNING
Electric Shock Hazard
Disconnect power before 
servicing.
Replace all parts and panels 
before operating.
Failure to do so can result in 
death or electrical shock.
Replacement heating elements must be of the same style 
and voltage/wattage rating as the ones originally in the water 
heater. This information can be found on the  fl ange or terminal 
block of the element or on the water heater data plate.
IMPORTANT: Before replacing any element, con fi rm 
 that 
you have the correct replacement element (wattage). This 
water heater has a 4500 watt upper element and a 4500 
watt lower element. DO NOT replace the element(s) with a 
wattage different than the ones speci fi ed for the upper and/
or lower element. 
IMPORTANT: Using an element greater than 4500 watts 
will damage the water heater and void the warranty
 .
1.  Turn off the power to the water heater.
2. 
 Drain the water heater as directed in the “Draining   
and Flushing” section. 3.  Remove the access cover(s), then take off the white 
fiber dam.
4.  Remove the protective plastic cover(s) over the  elements from their attachment point. 
5. 

Disconnect the electrical wires from the heating 
element(s) by loosening the screws (Figure 15). 
Remove the screw-in element(s) by turning the 
element(s) counterclockwise with a 1-1/2 inch socket 
wrench. Remove the existing gasket(s)
6.  Clean the area where the gasket(s) fits to the tank  and internal threads. If you are replacing the bottom 
element, remove any accumulated sediment on the 
bottom of the tank.
7. 

Make sure the replacement element(s) has the correct  
voltage and wattage rating by matching it to the rating 
plate on the water heater. Position the new gasket(s)  
on the element and insert it into the water heater tank 
(Figure 16).
NOTE: Apply a light coat of hand dishwashing soap 
and water to the gasket. Tighten the element by turning 
it clockwise until secure.
8.  Close the drain valve and open the nearest hot water   faucet. Then open the cold water shut off valve  and 
allow the tank to fill completely with water

.  To purge 
the lines of any excess air and sediment, keep the hot 
water faucet open for 3 minutes after a constant flow of 
water is obtained.
9.  Check for leaks around the element(s).
10.  Reconnect the electrical wires to the element and  securely tighten the screws (Figure 15).
11. Replace the  protective plastic cover(s) removed earlier. 
Make sure the cover(s) are securely engaged on the 
attachment point(s).
12. 

Replace the white fiber dam and access cover(s).
13.  Although this water heater is equipped with “Dry Fire”  protection circuitry, be sure tank is completely filled with 
water before applying electrical power to the water heater.
14.  Reconnect electrical power to the water heater at the  circuit breaker/fuse box.
15.  Set the desired water temperature and operating mode.  NOTE: 
 The water heater will conduct a system 
diagnostic (approximately 8 minutes) prior to operation. 
						

							17
DIAGNOSTIC CODES 
DISPLAY SHOWSINDICATES CORRECTIVE ACTION
EUCUpper element is not functioning 1.  Turn off power at the circuit breaker/fuse box and check for 
a loose connection at the element. For access directions 
see “Heating Element Replacement” section. If error persists 
proceed to the next step.
2.  Replace non-functioning element. See “Heating Element  Replacement” section.
ELC Lower element is not functioning 1.  Turn off power at the circuit breaker/fuse box and check for 
a loose connection at the element. For access directions 
see “Heating Element Replacement” section. If error persists 
proceed to the next step.
2. Replace  non-functioning  element. See “Heating Element 
Replacement” section.

 
SF The air filter is dirty. 1.  Turn off power at the circuit breaker/fuse box.
2.    Clean the air filter. See “Air Filter Cleaning/Replacement”  section. 
ECF The heat pump compressor is 
starting/stopping frequently. 1.  Turn off power at the circuit breaker/fuse box.
2.  Clean the air filter. See “Air Filter Cleaning/Replacement” 
section.
3.  If error persist, please contact a qualified person to check the  fan wire connection.
E20 or E21 Upper Temperature Sensor is not 
functioning.
Contact a qualified person to service the unit.
E30 or E31
Lower Temperature Sensor is not 
functioning.
E50 or E51 Heat Pump Suction Temperature 
Sensor is not functioning.
E10 or E11 Heat Pump Coil Temperature 
Sensor is not functioning.
E40 or E41 Heat Pump Discharge  
Temperature Sensor is not 
functioning.
Edr Not enough water in the tank 
(tank not full). Fill completely-Open all hot water taps in home and run until water 
(uninterupted) flows from all open hot water taps.
EPL Power supply voltage is too low. Check the power supply to the unit and make sure it is higher than 
204V
EDH Heat Pump Discharge 
Temperature is too high. Contact a qualified technician to service the unit. 
EoF
(If Accessory Condensate 
Pump is installed) Condensate pump failure. 1.  Check to see if accessory condensate pump is plugged in and 
has power. Also check circuit breaker/fuse box and GFCI (if 
used). If error persists, proceed to the next step.
2.  Check condensate pump outlet tube for blockage. If error  persists, proceed to the next step.
3.  Check control wire connections to condensate pump. If error  persists, proceed to the next step.
4.  Replace accessory condensate pump. If error persists, contact  a qualified technician to service the unit.
ECL Heat pump suction pressure is 
too low.
Contact a qualified technician to service the unit
EEE
EEPROM failure
ECC Heat pump compressor is not 
functioning.
“-”,”--”,”---” Unit is doing a system diagnostic.
No action is necessary.
ICE
Heat pump is in defrosting cycle.
HPO Heat pump is out of operation 
envelope.
NOTE: The diagnostic codes listed above are the most common. If a diagnostic c\
ode not listed above is displayed, 
contact Residential Technical Assistance referencing the number on the front of this manual. 
						

							18
TROUBLESHOOTING CHART
PROBLEMPOSSIBLE CAUSE(S) CORRECTIVE ACTION
NO HOT WATER1.  No power to the water heater (No 
lights on the unit are on).
2. 
Unit in Vacation mode
3.  High temperature limit switch open
4.  Hot water usage pattern exceeds the  capability of the water heater in 
current mode
5.  Non-functioning upper temperature  sensor 1.  Check for blown fuse or tripped breaker.
Restore power to unit.
2. 
Press Mode/Enter button and return to desired 
operating mode.
3.  Reset the high temperature limit switch; see  “Safety shut-off” section for more information.
4.  Change to different mode or modify usage pat- terns.
5.  Contact a qualified person for service.
INSUFFICIENT HOT WATER/ 
SLOW HOT WATER 
RECOVERY 1.  Temperature set-point too low
2. 

Air filter dirty
3.  Hot water usage pattern exceeds the  capability of the water heater in 
current mode
4.  Water connections to unit reversed
5.  Heat lost through long run of exposed  pipe
6.  Hot water leak at faucet or piping
7.  Non-functioning heating element
8.  Sediment or scale build up in tank 1.  Increase set point temperature; see “Adjusting 
the User Interface Module” section
2. 
Clean air filter
3.  Change to different mode or modify usage  patterns (For example if in Efficiency Mode 
switch to Hybrid Mode)
4.  Ensure the cold connection is at the bottom  and that the hot connection is at the top
5.  Insulate exposed piping
6.  Repair hot water leaks
7.  Call qualified person for service
8.  Drain and flush tank.  Water conditioning may  be necessary to minimize build up
HIGH OPERATION COSTS 1.  Temperature set-point too high
2. 

Air filter dirty
3.  Electric mode selected
4.  Water connections to unit reversed
5.  Heat lost thru long run of exposed  pipe
6.  Hot water leak at faucet or piping
7.  Sediment or scale build up in tank 1.  Decrease set point temperature; see “Adjusting 
the User Interface Module”
2.  Clean air filter
3.  Change to Efficiency or Hybrid mode for re- duced energy costs
4.  Ensure the cold connection is at the bottom  and that the hot connection is at the top
5.  Insulate exposed piping
6.  Repair hot water leaks
7.  Drain and flush tank.  Water conditioning may  be required to minimze build up
DRIP FROM TEMPERATURE & 
PRESSURE RELIEF V
 ALVE
(Warning: Do not plug or cap 
T&P discharge pipe.) 1.  Excessive water pressure
2.  Add or service a thermal expansion 
tank.
3. Non-functioning 

Temperature & 
Pressure Relief Valve 1.  Check water supply inlet pressure. If higher than 
80 PSIG, install a  pressure reducing valve (50-
60 PSIG is the recommended pressure.)
2.  See “Closed System/Thermal Expansion” section
3. 
Replace the Temperature & PressureRelief 
Valve
OTHER 1.  The water heater does not 
immediately start 
2. 

The heat pump does not run in 
Efficiency mode. 1.  When first started the water heater takes about 8 
minutes to complete a diagnostic routine
2. 
Contact a qualified person for service 
						

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REPAIR PART ILLUSTRATION
ITEMNO.PARTS DESCRIPTION
1
Element Access  Cover
2Element (4500 Watts)
3Energy Cut-Off (ECO) Switch 
4Temperature & Pressure Relief Valve (T&P)
5Dip Tube (at hot water outlet)
6Anode
7Controller
8Air Filter
9Fan Assembly
10Drain Valve
11Element Terminal Cover
12Ambient / Coil / Discharge Temperature Sensor*
13Upper / Lower Tank Temperature Sensor*
14Fan Shroud
15Condensate Drain Connection Cover 
16Electronic Expansion Valve Coil
17Start Capacitor*
18Relay Kit*
REPAIR PARTS
Repair parts may be ordered through your plumber, local 
distributor, home improvement center, or by calling
1-800-527-1953. When ordering repair parts always give 
the following information:
1.  Model, serial and product number
2. Item number
3. Parts description
REPAIR PARTS LIST
* NOT SHOWN
1
1
5
3
2
2
4
7
8
9
6
10
16
14
15
11
11
Figure 17 
						

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P.O. Box 1597, 500 Princeton Road, Johnson City, TN 37605
Technical Support: 800-999-9515 • Parts: 800-433-2545 • Fax: 800-64\
4-9306 www.americanwaterheater.com 
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