Friedrich KUHL R-410A - Manual (Page 66)

65
HEAT PUMP ROOM AIR CONDITIONERS: TROUBLE SHOOTING TIPS
ELECTRICAL TROUBLESHOOTING CHART - HEAT PUMP
Reversing Valve Stuck
Replace the Reversing Valve
Replace the Solenoid Coil
NO
Is the Solenoid Coil Good?
Is Line Voltage
Present at the Solenoid
Is the Selector Switch
Set for Heat?
NO
SYSTEM COOLS WHEN
HEATING IS DESIRED.
YES
HEAT PUMP
YES
Noncondensables (air)
in System
Overcharged
Low Airfl ow Across
Indoor Coil
Outdoor Ambient Too High
For Operation In Heating
Moisture in System Defective Compressor Defective Compressor
Undercharged Overcharged Undercharged
Refrigerant System
Restriction
Reversing Valve not
Fully Seated
Low Airfl ow
Across Outdoor Coil
Outdoor Ambient Too High
for Operation in Heating
Refrigerant System
Restriction
Reversing Valve not
Fully Seated
REFRIGERANT SYSTEM DIAGNOSIS - HEATING CYCLE
LOW SUCTION PRESSURE HIGH SUCTION PRESSURE LOW HEAD PRESSURE HIGH HEAD PRESSURE