Friedrich R-410A Refrigerant System Diagnosis - Cooling Cycle, Troubleshooting Chart - Heat Pump

HEAT PUMP ROOM AIR CONDITIONERS: TROUBLE SHOOTING TIPS

Problem	Possible Cause	Action
	Incorrect wiring	Refer to applicable wiring diagram
	Defective solenoid coil	Check for continuity of coil
Unit cools when		Block condenser coil & switch unit to cooling.
		Allow pressure to build up in system, then
heat is called for	Reversing valve fails to shift
		switch to heating. If valve fails to shift, replace
		valve.
	Inoperative system switch	Check for continuity of system switch

Problem	Possible Cause	Action
	Heating capillary tube partially	Check for partially starved outer coil. Replace
	restricted	heating capillary tube
		Switch unit several times from heating to
Cooling adequate,	Check valve leaking internally	cooling. Check temperature rise across
but heating		coil. Refer to specification sheet for correct
insufficient		temperature rise
	Reversing valve failing to shift	Denergize solenoid coil, raise head pressure,
		energize solenoid to break loose. If valve fails
	completely; bypassing hot gas
		to make complete shift, replace valve.

TROUBLESHOOTING CHART - HEAT PUMP

REFRIGERANT SYSTEM DIAGNOSIS - COOLING CYCLE

LOW SUCTION PRESSURE HIGH SUCTION PRESSURE

LOW HEAD PRESSURE

HIGH HEAD PRESSURE

Low Load Conditions

Low Air Flow Across

Indoor Coil

Refrigerant System

Restriction

Undercharged

High Load Conditions

High Air Flow Across

Indoor Coil

Reversing Valve not

Fully Seated

Overcharged

Low Load Conditions

Refrigerant System

Restriction

Reversing Valve not

Fully Seated

Undercharged

in System

High Load Conditions

Low Air Flow Across

Outdoor Coil

Overcharged

Noncondensables (air)

Moisture in System

Defective Compressor

Defective Compressor

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