Hoshizaki KM-650MAH, KM-650MRH, KM-650MWH service manual Evaporator is Frozen Up

2. Evaporator is Frozen Up

Problem	Possible Cause		Remedy
[1]Freeze cycle time is	a)Float Switch	1. Leads short-circuit or	1. Check and replace.
too long.		defective switch.
		2. Float does not move	2. Clean or replace.
		freely.
	b)Inlet Water Valve	1. Diaphragm does not	1. Check for water leaks with
		close.	icemaker off.
	c) Control Board	1. Defective.	1. See "II.C.4. Control Board
			Check Procedure."
[2]All ice formed on	a)Evaporator	1. Scaled up.	1. Clean.
evaporator does not
	b)Water Supply Line	1. Water pressure too	1. Check and get
fall into bin in harvest
cycle.		low.	recommended pressure.
	c) Water Filter System	1. Dirty/Restricted	1. Replace filter.
	d)Inlet Water Valve	1. Dirty mesh filter or	1. Clean.
		orifice.
		2. Diaphragm does not	2. Check for water leaks with
		close.	icemaker off.
	e) Ambient and/or water	1. Too cool.	1. Increase temperature.
	temperature.
	f) Line Valve	1. Continues to open in	1. Check operation in harvest
		harvest cycle.	cycle and replace.
	g)Thermistor	1. Out of position or	1. See "V.I. Removal
		loose attachment.	and Replacement of
			Thermistor."
	h)Control Board	1. Harvest timer is set	1. Adjust longer, referring
		too short.	to "II.C.3. Controls and
			Adjustments, c) Harvest
			Timer.
		2. Defective.	2. See "II.C.4. Control Board
			Check Procedure."
[3]Other	a)Spray Tubes	1. Clogged.	1. Clean
		2. Out of position.	2. Place in position.
	b)Water System	1. Dirty.	1. Clean.
	c) Refrigerant	1. Undercharged.	1. Check for leaks and
			recharge.
	d)Expansion Valve	1. Bulb out of position or	1. Place in position.
		loose attachment.
		2. Defective.	2. Replace.
	e)Hot Gas Valve	1. Coil winding opened.	1. Replace.
		2. Plunger does not	2. Replace.
		move.
		3. Wiring to hot gas	3. Check for loose
		valve.	connection or open, and
			replace.
	f) Ice Cube Guide	1. Out of position and ice	1. Place in position.
		trapped.

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