Friedrich QUIETMASTER 2008 Service Manual page 49

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