Troubleshooting - A.O. Smith AHPW-25 User's Information Manual

Problem
Heat Pump is too noisy
Water on fl oor around the
heat pump and or water
tank
Heat Pump is not running
- Electrical issues
Heat Pump is not running
- High Pressure Fault
Heat Pump is not running
- Low Pressure Fault
Water is never hot enough
*Reset the heat pump by removing then restoring power to the unit at the breaker or from the manual switch. (There will be a three minute delay before heat
pump restarts.) If the heat pump cuts out again on LOW or HIGH PRESSURE, additional troubleshooting is necessary to fi nd the cause.
DO NOT CONTINUE TO RESET THE HEAT PUMP, AS CONTINUED SHORT-CYCLING MAY STRESS OR DAMAGE INTERNAL COMPONENTS

TROUBLESHOOTING

Possible Causes
1. Sheet Metal fasteners are loose.
2. Operating vibration is transferring to fl oor or
building structure.
3. Blower pulley assembly loose or out of
alignment
1. Tubing, valves, or fi ttings are leaking
2. Heat Pump is not leveled causing drain pan
overfl ow
3. Condensate trap not installed properly
4. Drain pan overfl owing
5. Condensation forming on the bottom of unit
(humid environments)
1. Circuit does not have adequate ampacity
2. Short circuit or loose connection in fi eld wiring
3. Short circuit or loose connection in the
cabinet
4. Thermostat Failure
5. Defective anti-short cycle timer
6. Compressor burn-out
1. Thermostat setting too high
2. Air temperature over 95° F
3. Low water fl ow causes
a. External Pump is not operating
b. Piping between the heat pump and storage
tank exceeds 50 equivalent feet
c. Heat exchanger has scale buildup
d. Shut off valves are partially closed
1. Room temperature below 40° F
2. Blower not operating at nameplate CFM -
blower belt is broken or out of alignment
fi lters are dirty
3. Unit does not have adequate clearances
obstructing air fl ow
4. Loss of Refrigerant
1. Thermostat setting is too low
2. Heat pump/storage tank undersized for
application
3. Heat pump is not properly connected to
storage tank.
4. Unit cooling coil is over cooling the space
Corrections
Tighten Fasteners
Place vibration dampers underneath unit
Tighten or align pulleys
Repair leaks as necessary
Shim unit to level, See installation section
Condensate trap depth must maintain a water column
during operation
Use pipe snake or compressed air to remove obstruction
Cover bottom of unit with foam insulation
Refer to nameplate for unit requirements
Check fi eld wiring diagram, Tighten all connections
Check for loose wiring and tighten
Replace thermostat
Reset phase monitor
Replace Compressor (refer to compressor change-out
page)
Thermostat setting should not exceed 160° F
Keep heat pump off until room temperature is back in
operating range
Low water fl ow corrections
Replace unit pump
Reduce piping or add booster pump
Clean heat exchanger with a mild acid wash
Open all shut off valves
Keep heat pump off until room temperature is back in
operating range
Correct air-fl ow issue
i. Replace or realign pulley assembly; tighten belt at
the adjustable pulley
ii. Replace fi lters
iii. Relocate unit to allow for even air fl ow
Find source of leak, repair, and recharge
Set thermostat for storage tank to a higher temperature
Increase size of storage tank or install gas or electric
heater to make up for shortfall
Refer to fi eld piping diagrams for recommended piping
If the room air temperature is too cool a) Use back up
water heating b) Duct cool air to another space c) duct
warmer air from another space to the installed room
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