Friedrich R-410A service manual Problem, Possible Cause, Action

HEAT / COOL ONLY ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS

Problem	Possible Cause	Action
	Heat anticipator (resistor) shorted (on applicable	Disconnect power to unit. Remove resistor from
		t-stat bulb block. Plug in unit & allow to operate.
	models)
		Feel resistor for heat. If not heat, replace resistor
Room temperature
uneven	Wide differential - partial loss of t-stat bulb charge	Replace t-stat
(Heating cycle)
		Refer to appropriate wiring diagram. Resistor is
	Incorrect wiring	energized during "ON" cycle of compressor or
		fan.

Problem	Possible Cause	Action
	Opened doors or windows	Close doors or windows.
	Dirty filter	Clean as recommended in Owner's Manual
		Check heat rise across coil. If unit operates
	Unit undersized	efficiently, check if insulation can be added
		to attic or walls. If insulation is adequate,
Does not heat		recommend additional unit or larger one
adequately	Heater hi-limit control cycling on & off	Check for adequate fan air across heater. Check
		control for open at 110°F & close at 100°F
	Shorted or opened heater	Ohmmeter/continuity check
	Incorrect wiring	Check applicable wiring diagram

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