Hoshizaki 73168 service manual Cabinet Defrost

4. Cabinet Defrost

Problem		Possible Cause			Remedy
[1]	Cabinet fan motors	a) Cabinet Fan Relay	1.	Bad contacts (closed).	1.	Check for continuity and
	on.					replace.
		b) Control Board	1.	Defective.	1.	Replace.
[2]	Evaporator does	a) Defrost Thermistor	1.	Defective.	1.	See "II.E. Thermistor
	not defrost					Check."
	completely.	b) Defrost	1.	Not enough defrosts	1.	Factory default is once
				occurring per day.		every 6 hours. See "II.D.5.
				Operation in humid		Service Menu."
				conditions.
		c) Defrost Heater	1.	Defective.	1.	Replace heater.
		d) Defrost Thermostat	1.	Defective, turning off	1.	Replace defrost thermostat.
				heaters prematurely,
				or fused open.
		e) Cabinet Liquid Line	1.	Does not close.	1.	Check and replace.
		Valve
[3]	Defrost cycle too	a) Defrost	1.	Not enough defrosts	1.	Factory default is once
	long. (E3 Defrost			occurring per day.		every 6 hours. See "II.D.5
	Alarm)			Operation in humid		Service Menu."
				conditions.
		b) Defrost Thermistor	1.	Defective.	1.	Replace.
		c) Defrost Heater	1.	Defective.	1.	Replace heater.
		d) Defrost Thermostat	1.	Defective, turning off	1.	Replace defrost thermostat.
				heaters prematurely,
				or fused open.
		e) Control Board	1.	Defective.	1.	Replace.

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