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Table 16 - Troubleshooting
Fault
Heating
Cooling
Possible cause
Solution
Main power problems
X
X
Green status LED Off
Check line voltage circuit breaker and disconnect.
Check for line voltage between L1 and L2 on the contactor.
Check for 24 V a.c. between R and C on controller.
Check primary/secondary voltage on transformer.
HP fault - code 2
X
Reduced or no water flow in cooling
Check pump operation or valve operation/setting.
High pressure
Check water flow adjust to proper flow rate.
X
Water temperature out of range in cooling
Bring water temperature within design parameters.
X
Reduced or no airflow in heating
Check for dirty air filter and clean or replace.
Check fan motor operation and airflow restrictions.
Dirty air coil - construction dust etc.
External static too high. Check Table 4.
X
Air temperature out of range in heating
Bring return air temperature within design parameters.
X
X
Overcharged with refrigerant
Check superheat/subcooling vs typical operating condition Table 9.
X
X
Bad HP switch
Check switch continuity and operation. Replace.
LP/LOC fault - code 3
X
X
Insufficient charge
Check for refrigerant leaks.
Low pressure/loss of charge
X
Compressor pump down at start-up
Check charge and start-up water flow.
FP1 fault - code 4
X
Reduced or no water flow in heating
Check pump operation or water valve operation/setting.
Water freeze protection
Plugged strainer or filter. Clean or replace.
Check water flow adjust to proper flow rate.
X
Inadequate anti-freeze level
Check anti-freeze density with hydrometer.
X
Improper freeze protect setting
Clip JW2 jumper for anti-freeze (-12.2
°
C) use.
(-1.1
°
C vs -12.2
°
C)
X
Water temperature out of range
Bring water temperature within design parameters.
X
X
Bad thermistor
Check temperature and impedance correlation.
FP2 fault - code 5
X
Reduced or no airflow in cooling
Check for dirty air filter and clean or replace.
Air coil freeze protection
Check fan motor operation and airflow restrictions.
External static too high. Check Table 4.
X
Air temperature out of range
Too much cold vent air. Bring entering air temperature within design
parameters.
X
Improper freeze protect setting
Normal airside applications will require -1.1
°
C only.
(-1.1
°
C vs -12.2
°
C)
X
X
Bad thermistor
Check temperature and impedance correlation.
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
X
X
Under voltage
Check power supply and 24 V a.c. voltage before and during operation.
(Auto resetting)
Check power supply wire size.
Check compressor starting.
Check 24 V a.c. and unit transformer tap for correct power supply voltage.
X
X
Over voltage
Check power supply voltage and 24 V a.c. before and during operation.
Check 24 V a.c. and unit transformer tap for correct power supply voltage.
Performance Monitor -
X
Heating mode FP2> 51.7
°
C
Check for poor airflow or overcharged unit.
code 8
X
Cooling mode FP1> 51.7
°
C
Check for poor water flow or airflow.
or FP2< 4.4
°
C
FP1 and FP2 thermistors -
X
FP1 temperature is higher
Swap FP1 and FP2 thermistors.
code 9
than FP2 temperature.
X
FP2 temperature is higher
Swap FP1 and FP2 thermistors.
than FP1 temperature.
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.
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.
Legend
RV - Reversing valve
