Hoshizaki MWH(-M), MWH KM-515MAH, MRH/3, MRH KM-901MAH Low Ice Production, Freeze-Up Possible Cause

Freeze-Up - Possible Cause

11. Thermostatic Expansion Valve	a) Defective.
12. Hot Gas Valve	a) Closed or restricted.
13. Liquid Line Valve	a) Open.
	Freeze Cycle
1. Evaporator	a) Scaled up.
	b) Damaged.
2. Spray Tubes and/or Spray	a) Dirty.
Guides	b) Out of position.
3. Refrigerant Charge	a) Low.
4. Control Board	a) Freeze timer (S4 dip switch 9 & 10) set incorrectly.
See "II.C. Control Board Check"
	b) Defective.
5. Inlet Water Valve	a) Leaking by.
6. Float Switch	a) Float does not move freely.
See "II.E. Float Switch Check
	b) Defective.
and Cleaning"
7. Pump Motor	a) RPM too slow.
	b) Impeller damaged.
8. Thermostatic Expansion Valve	a) Bulb loose or defective.
9. Liquid Line Valve	a) Restricted.
10. Headmaster (C.P.R.)	a) Not bypassing.
(remote models)

3. Low Ice Production

Low Ice Production - Possible Cause

	Long Harvest Cycle
1. Evaporator	a) Scaled up.
2. Spray Tubes and/or Spray	a) Dirty.
Guides
	b) Out of position.
3. Refrigerant Charge	a) Low.
4. Water Supply	a) Low water pressure.
	b) External water filters clogged.
	c) Insufficient water line size.
	Minimum 1/4" Nominal ID (6 mm Nominal OD in the EU) water
	tubing or equivalent.
	d) Too cold.
5. Control Board	a) Thermistor connection loose (K3).
See "II.C. Control Board Check"	b) Defective.
6. Thermistor	a) Loose, disconnected, or defective.
See "II.F. Thermistor Check"
7. Hot Gas Valve	a) Erratic or closed.
8. Inlet Water Valve	a) Screen or orifice clogged.
9. Compressor	a) Inefficient or off.
10. Liquid Line Valve	a) Erratic or open.
11. Thermostatic Expansion Valve	a) Defective.

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