Carrier AQUAZONE 50HQL072-120 Installation, Start-up And Service Instructions Manual

Carrier AQUAZONE 50HQL072-120 Installation, Start-up And Service Instructions Manual Manual pdf 41 page image

41Table 27 — Troubleshooting (cont)LEGENDFAULT HEATING COOLING POSSIBLE CAUSE SOLUTIONOnly Compressor Runs X X Thermostat wiring Check G wiring at heat pump. Jumper G and R for fan operation.X X Fan motor relay Jumper G and R for fan operation. Check for line voltage across BRcontacts.Check fan power enable relay operation (if present).X X Fan motor Check for line voltage at motor. Check capacitor.X X Thermostat wiring Check Y and W wiring at heat pump. Jumper Y and R for compressoroperation in test mode.Unit Does Not Operate inCooling 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 whileoperating 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.Insufficient Capacity/Not Cooling or HeatingProperlyX X Dirty filter Replace or clean.X Reduced or no airflow inheating Check for dirty air filter and clean or replace.Check fan motor operation and airflow restrictions.Too high external static. Check blower Tables 6-16.X Reduced or no airflow incooling Check for dirty air filter and clean or replace.Check fan motor operation and airflow restrictions.Too high external static. Check blower Tables 6-16.X X Leaky ductwork Check supply and return air temperatures at the unit and at distant ductregisters if significantly different, duct leaks are present.X X Low refrigerant charge Check superheat and subcooling.X X Restricted metering device Check superheat and subcooling. Replace.X Defective reversing valve Perform RV touch test.X X Thermostat improperlylocated Check location and for air drafts behind thermostat.X X Unit undersized Recheck loads and sizing check sensible cooling load and heat pumpcapacity.X X Scaling in water heatexchanger Perform Scaling check and clean if necessary.X X Inlet water too hot or cold Check load, loop sizing, loop backfill, ground moisture.High Head Pressure X Reduced or no airflow inheating Check for dirty air filter and clean or replace.Check fan motor operation and airflow restrictions.Too high external static. Check blower Tables 6-16.X Reduced or no water flow incooling Check pump operation or valve operation/setting.Check water flow adjust to proper flow rate.X Inlet water too hot Check load, loop sizing, loop backfill, ground moisture.X Air temperature out of rangein heating Bring return-air temperature within design parameters.X Scaling in water heatexchanger Perform scaling check and clean if necessary.X X Unit overcharged Check superheat and subcooling. Reweigh in charge.X X Non-condensables insystem Evacuate refrigerant, re-charge the system, and then weigh the newrefrigerant charge.X X Restricted metering device Check superheat and subcooling. Replace.Low Suction Pressure X Reduced water flow inheating Check pump operation or water valve operation/setting.Plugged strainer or filter. Clean or replace.Check water flow adjust to proper flow rate.X Water temperature out ofrange Bring water temperature within design parameters.X Reduced airflow in cooling Check for dirty air filter and clean or replace.Check fan motor operation and airflow restrictions.Too high external static. Check blower Tables 6-16.X Air temperature out of range Too much cold vent air. Bring entering air temperature within designparameters.X X Insufficient charge Check for refrigerant leaks.Low Discharge AirTemperature in HeatingX Too high airflow Check blower Tables 6-16.X Poor performance See 'Insufficient Capacity'.High Humidity X Too high airflow Check blower Tables 6-16.X Unit oversized Recheck loads and sizing check sensible cooling load and heat pumpcapacity.FP — Freeze Protection LP/LOC — Low Pressure/Loss of ChargeHP — High Pressure RV — Reversing ValveLED — Light Emitting Diode

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