Heat Controller REG-123A, REG-71A service manual Troubleshooting Guide

		Troubleshooting Guide
COMPLAINT	CAUSE	REMEDY
Compressor will not run,	Thermostat	Check the position of knob If not at the coldest set-
but fan motor runs.		ting, advance the knob to this setting and restart
		unit.
		Check continuity of the thermostat. Replace ther-
		mostat if circuit is open.
	Capacitor (Discharge	Check the capacitor.
	capacitor before servicing.)	Replace if not within ±10% of manufacturers rat-
		ing. Replace if shorted, open, or damaged.
	Compressor	Check the compressor for open circuit or ground. If
		open or grounded, replace the compressor.
	Overload	Check the compressor overload, if externally
		mounted. Replace if open. (If the compressor tem-
		perature is high, remove the overload, cool it, and
		retest.)
Compressor cycles on	Voltage	Check the voltage.
overload.		If not within limits, call an electrician.
	Overload	Check overload, if externally mounted.
		Replace if open. (If the compressor temperature is
		high, remove the overload, cool, and retest.)
Compressor cycles on	Fan motor	If not running, determine the cause. Replace if
overload.		required.
	Condenser air flow restric-	Remove the cabinet. inspect the interior surface of
	tion	the condenser; if restricted, clean carefully with a
		vacuum cleaner (do not damage fins) or brush.
		Clean the interior base before reassembling.
	Condenser fins (damaged)	If condenser fins are closed over a large area on
		the coil surface, head pressures will increase,
		causing the compressor to overload. Straighten
		the fins or replace the coil.
Compressor cycles on	Capacitor	Test capacitor.
overload.	Wiring	Check the terminals. If loose, repair or replace.
	Refrigerating system	Check the system for a restriction.
Insufficient cooling or heat-	Air filter	If restricted, clean of replace.
ing
	Exhaust damper door	Close if open.
	Unit undersized	Determine if the unit is properly sized for the area
		to be cooled.
Excessive noise	Blower or fan	Check the set screw or clamp. If loose or missing,
		correct. If the blower or fan is hitting air guide,
		rearrange the air handling parts.
	Copper tubing	Remove the cabinet carefully and rearrange tubing
		not to contact cabinet, compressor, shroud, and
		barrier.
Auto air-swing fails.	Rotary switch.	Set the knob to HIGH COOL or LOW COOL while
		rocker switch is ON.
	Wiring	Check terminals. If loose, repair or replace.
	Synchronous motor.	Check the synchronous motor for open circuit.

Service Manual 27