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Table 39 — WSHP Troubleshooting (cont)
LEGEND
FAULT HEATING COOLING POSSIBLE CAUSE SOLUTION
Condensate Fault —
Code 6
X X Blocked drain Check for blockage and clean drain.
X X Improper trap Check trap dimensions and location ahead of vent.
X Poor drainage Check for piping slope away from unit.
Check slope of unit toward outlet.
Poor venting. Check vent location.
X Moisture on sensor Check for moisture shorting to air coil.
Over/Under Voltage —
Code 7 (Auto Resetting)
X X Under voltage Check power supply and 24 vac voltage before and during
operation.
Check power supply wire size.
Check compressor starting.
Check 24 vac and unit transformer tap for correct power supply
voltage.
X X Over voltage Check power supply voltage and 24 vac before and during operation.
Check 24 vac and unit transformer tap for correct power supply
voltage.
Performance Monitor —
Code 8
X Heating mode FP2>125 F Check for poor airflow or overcharged unit.
X Cooling mode FP1>125 F OR
FP2< 40 F
Check for poor water flow or airflow.
FP1 and FP2 Thermistors
— Code 9
X FP1 temperature is higher
than FP2 temperature.
Swap FP1 and FP2 thermistors.
X FP2 temperature is higher
than FP1 temperature.
Swap FP1 and FP2 thermistors.
No Fault Code Shown X X No compressor operation See Scroll Compressor Rotation section.
X X Compressor overload Check and replace if necessary.
X X Control board Reset power and check operation.
Swapped Thermistor —
Code 9
X X FP1 and FP2 swapped Reverse position of thermistors.
Unit Short Cycles X X Dirty air filter Check and clean air filter.
X X Unit in 'Test Mode' Reset power or wait 20 minutes for auto exit.
X X Unit selection Unit may be oversized for space. Check sizing for actual load of space.
X X Compressor overload Check and replace if necessary.
Only Fan Runs X X Thermostat position Ensure thermostat set for heating or cooling operation.
X X Unit locked out Check for lockout codes. Reset power.
X X Compressor overload Check compressor overload. Replace if necessary.
X X Thermostat wiring Check Y and W wiring at heat pump. Jumper Y and R for compressor
operation in Test mode.
Only Compressor Runs X X Thermostat wiring Check G wiring at heat pump. Jumper G and R for fan operation.
Check Y and W wiring at heat pump. Jumper Y and R for compressor
operation in test mode.
X X Fan motor relay Jumper G and R for fan operation. Check for line voltage across BR
contacts.
Check fan power enable relay operation (if present).
X X Fan motor Check for line voltage at motor. Check capacitor.
Unit Does Not Operate in
Cooling
X Reversing valve Set for cooling demand and check 24 vac on RV coil and at control.
If RV is stuck, run high pressure up by reducing water flow and while
operating, engage and disengage RV coil voltage to push valve.
X Thermostat setup Check for 'O' RV setup not 'B'.
X Thermostat wiring Check O wiring at heat pump. Jumper O and R for RV coil 'Click'.
Insufficient Capacity/
Not Cooling or Heating
Properly
X X Dirty filter Replace or clean.
X Reduced or no airflow in
heating
Check for dirty air filter and clean or replace.
Check fan motor operation and airflow restrictions.
External static too high. Check blower performance per
Tables 11-13.
X Reduced or no airflow in
cooling
Check for dirty air filter and clean or replace.
Check fan motor operation and airflow restrictions.
External static too high. Check blower performance per
Tables 11-13.
X X Leaky ductwork Check supply and return air temperatures at the unit and at distant duct
registers if significantly different, duct leaks are present.
X X Low refrigerant charge Check superheat and subcooling per Tables 20-30.
X X Restricted metering device Check superheat and subcooling per Tables 20-30. Replace.
X Defective reversing valve Set for cooling demand and check 24 vac on RV coil and at control.
If RV is stuck, run high pressure up by reducing water flow and while
operating, engage and disengage RV coil voltage to push valve.
X X Thermostat improperly located Check location and for air drafts behind thermostat.
X X Unit undersized Recheck loads and sizing check sensible cooling load and heat pump
capacity.
X X Scaling in water heat exchanger Perform condenser cleaning.
X X Inlet water too hot or cold Check load, loop sizing, loop backfill, ground moisture.
LED — Light-Emitting Diode
RV — Reversing Valve
TXV —
Thermostatic Expansion Valve