Friedrich WS10B10 service manual Problem, Possible Cause, Possible Solution

HEAT/COOL ONLY ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS

Problem	Possible Cause	Possible Solution
Room temperature	Bad indoor ambient thermistor	Check error codes. Replace if needed.
uneven
	Opened doors, windows, etc.	Close doors, windows, etc.
(Heating cycle)

Problem	Possible Cause	Possible Solution
	Incorrect wiring	Refer to appropriate wiring diagram
Unit will not	Bad outdoor coil thermistor or	Check error codes. Replace needed part.
	electronic control board
defrost
	Outdoor temperature below	Ambient temperature will have to
		rise above 32 degrees F for frost
	32 degrees
		to melt

Problem	Possible Cause	Possible Solution
	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,
		recommend additional unit or larger one
Does not heat	Outdoor t-stat open (applicable	T-stat should close at 38°F. Check continuity
		of control. If temperature is below 38°F,
	models)
adequately		replace control
	Heater hi-limit control cycling on &	Check for adequate fan air across heater.
		Check control for open at 160°F & close at
	off
		150°F
	Shorted supplementary heater	Ohmmeter check, approx. 32-35 ohms
	Incorrect wiring	Check applicable wiring diagram

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