Carrier AQUAZONE 50PTH Installation And Service Instructions Manual

53Table 32 — WSHP Troubleshooting (cont)LEGENDFAULT HEATING COOLING POSSIBLE CAUSE SOLUTIONHigh Head Pressure 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 9-13.X Reduced or no water flow incoolingCheck pump operation or valve operation/setting.Check water flow adjust to proper flow rate. See Tables 19 and 24.X Inlet water too hot Check load, loop sizing, loop backfill, ground moisture.X Air temperature out of range inheatingBring return-air temperature within design parameters.X Scaling in water heat exchanger Perform condenser cleaning.X X Unit overcharged Check superheat and subcooling. Reweigh in charge.X X Noncondensables in system Remove refrigerant, evacuate system and charge unit.X X Restricted metering device Check superheat and subcooling per Tables 20-23. Replace.Low Suction Pressure X Reduced water flow in heating 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 of range 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.External static too high. Check blower performance per Tables 9-13.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 performance per Tables 9-13.X Poor performance See “Insufficient Capacity.”High Humidity X Too high airflow Check blower performance per Tables 9-13X Unit oversized Recheck loads and sizing check sensible cooling load and heat pumpcapacity.Low Refrigerant SuctionPressureX Normal operation Check/compare with unit Installation Manual for typical operating temper-atures and pressures chart.X Reduced water flow Check pump operation.Check strainer or filter.Improper flow regulator.X Water temperature out of range Bring water temperature within proper range.X Scaling in water to refrigerantheat exchangerConduct water quality analysis.X Reduced airflow Check for dirty air filter.Check for dirty air coil.Check fan motor operation.External static pressure exceeds fan operating parameters.X X Return air temperature belowminimumSpace temperature too cold.Excessive fresh air.X Supply air bypassing to return airstream (zone systems).Check for leaking ductwork.X X Insufficient refrigerant charge Locate and repair leak.X X Improperly located TXV sensingbulbLocate bulb on suction line between reversing valve and compressor.X X Failed or restricted meteringdevice Failed TXV power head, capillary or sensing bulb.Plugged TXV strainer.High Refrigerant Superheat X X Insufficient refrigerant charge Locate and repair leak.X X Improperly located TXV sensingbulbLocate bulb on suction line between reversing valve and compressor.X X Failed or restricted meteringdeviceFailed TXV power head, capillary or sensing bulb.Plugged TXV strainer.High RefrigerantSubcoolingX X Excessive refrigerant charge Remove refrigerant as needed.X X Failed or restricted meteringdeviceFailed TXV power head, capillary or sensing bulb.Plugged TXV strainer.TXV and/or Low PressureTubing FrostingX Normal operation May occur when entering water temperature is close to minimum.X X Insufficient refrigerant charge Locate and repair leak.X X Failed or restricted meteringdeviceFailed TXV power head, capillary or sensing bulb.Plugged TXV strainer.Equalizer Line Condensingor FrostingX X Failed or restricted meteringdeviceFailed TXV power head, capillary or sensing bulb.Plugged TXV strainer.LED — Light-Emitting DiodeRV — Reversing ValveTXV — Thermostatic Expansion Valve