Carrier AQUAZONE 50HQP072-120 Installation And Service Instructions Manual page 31

FAULT HEATING COOLING
Main Power Problems
HP Fault — Code 2
High Pressure
LP Fault — Code 3
Low Pressure/Loss of
Charge
FP1 Fault — Code 4
Water Freeze Protection
FP2 Fault — Code 5
Air Coil Freeze
Protection
Condensate Fault —
Code 6
Over/Under Voltage —
Code 7
(Auto Resetting)
Performance Monitor —
Code 8
No Fault Code Shown
Unit Short Cycles
Only Fan Runs
LEGEND
FP — Freeze Protection
HP — High Pressure
LED — Light-Emitting Diode
LP — Low Pressure
RV — Reversing Valve
Table 18 — Troubleshooting
POSSIBLE CAUSE
X X Green Status LED Off
X Reduced or no water flow in
cooling
X Water temperature out of
range in cooling
X Reduced or no airflow in
heating
X Air temperature out of range
in heating
X X Overcharged with refrigerant Check superheat/subcooling vs. typical operating condition.
X X Bad HP switch
X X Insufficient charge
X Compressor pump down at
start-up
X Reduced or no water flow in
heating
X Inadequate antifreeze level
X Improper freeze protect set-
ting ( –1.1 Cvs –12.2 C )
X Water temperature out of
range
X X Bad thermistor
X Reduced or no airflow in
cooling
X Air temperature out of range Too much cold vent air. Bring entering-air temperature within design
X Improper freeze protect set-
ting ( –1.1 Cvs –12.2 C )
X X Bad thermistor
X X Blocked drain
X X Improper trap
X Poor drainage
X Moisture on sensor
X X Under voltage
X X Over voltage
X Heating mode FP2> 51.7 C
X Cooling mode FP1> 51.7 C
OR FP2< 4.4 C
X X Compressor overload
X X Control board
X X Dirty air filter
X X Unit in Test mode
X X Unit selection
X X Compressor overload
X X Thermostat position
X X Unit locked out
X X Compressor overload
X X Thermostat wiring
Check line voltage circuit breaker and disconnect.
Check for line voltage between L1 and L2 on the contactor.
Check for 24-vac between R and C on controller.
Check primary/secondary voltage on transformer.
Check pump operation or valve operation/setting.
Check water flow adjust to proper flow rate.
Bring water temperature within design parameters.
Check for dirty air filter and clean or replace.
Check fan motor operation and airflow restrictions.
Dirty air coil — construction dust, etc. Perform preventative mainte-
nance; Clean air coil.
High external static. Check duct design and downstream interference.
Bring return-air temperature within design parameters.
Check switch continuity and operation. Replace.
Check for refrigerant leaks.
Check charge and start-up water flow.
Check pump operation or water valve operation/setting.
Plugged strainer or filter. Clean or replace.
Check water flow adjust to proper flow rate.
Check antifreeze density with hydrometer.
Clip JW3 jumper for antifreeze ( –12.2 C ) use.
Bring water temperature within design parameters.
Check temperature and impedance correlation.
Check for dirty air filter and clean or replace.
Check fan motor operation and airflow restrictions.
High external static. Check duct design and downstream interference.
parameters.
Normal airside applications will require –1.1 C only.
Check temperature and impedance correlation.
Check for blockage and clean drain.
Check trap dimensions and location ahead of vent.
Check for piping slope away from unit.
Check slope of unit toward outlet.
Poor venting. Check vent location.
Check for moisture shorting to air coil.
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.
Check power supply voltage and 24 vac before and during operation.
Check 24-vac and unit transformer tap for correct power supply voltage.
Check for poor airflow or overcharged unit.
Check for poor water flow or airflow.
Check and replace if necessary.
Reset power and check operation.
Check and clean air filter.
Reset power or wait 20 minutes for auto exit.
Unit may be oversized for space. Check sizing for actual load of space.
Check and replace if necessary.
Ensure thermostat set for heating or cooling operation.
Check for lockout codes. Reset power.
Check compressor overload. Replace if necessary.
Check Y and W wiring at heat pump. Jumper Y and R for compressor
operation in Test mode.
31
SOLUTION