Evaporator Is Frozen Up - Hoshizaki KMD-901MWH Service Manual

2. Evaporator is Frozen Up

Problem
[1]Freeze cycle time is
too long.
[2]All ice formed on
evaporator does not
fall into bin in harvest
cycle.
[3]Other.
Possible Cause
a) Float Switch
b) Inlet Water Valve
c) Control Board
d) Water Pump
e) Spray Tubes
f) Evaporator
g) Expansion Valve
a) Evaporator
b) Water Supply Line
c) Water Filter System
d) Inlet Water Valve
e) Ambient and/or water
temperature.
f) Line Valve
(if applicable)
g) Thermistor
h) Control Board
i) Water Regulating Valve
(water-cooled model
only)
a) Spray Tubes
b) Water System
1. Leads short-circuit or
defective switch.
2. Float does not move
freely.
1. Diaphragm does not
close.
1. Defective.
1. RPM too slow.
1. Clogged.
1. Scaled up.
1. Operating erratically.
1. Scaled up.
1. Water pressure too
low.
1. Dirty/Restricted.
1. Dirty mesh filter or
orifice.
2. Diaphragm does not
close.
1. Too cool.
1. Continues to open in
harvest cycle.
1. Out of position or
loose attachment.
1. Harvest timer is set
too short.
2. Defective.
1. Leaking by in harvest. 1. Check and replace.
1. Clogged.
2. Out of position.
1. Dirty.
2. Water supply line too
small; requires 3/8"
OD line dedicated per
machine.
3. Water filter flow rate
too small.
38
Remedy
1. Check and replace.
2. Clean or replace.
1. Check for water leaks with
icemaker off.
1. See "II.C.4. Control Board
Check Procedure."
1. Check and replace.
1. Unclog.
1. Clean.
1. Check and replace.
1. Clean.
1. Check and get
recommended pressure.
1. Replace filter.
1. Clean.
2. Check for water leaks with
icemaker off.
1. Increase temperature.
1. Check operation in harvest
cycle and replace.
1. See "V.I. Removal
and Replacement of
Thermistor."
1. Adjust longer, referring
to "II.C.3. Controls and
Adjustments, b) Harvest
Timer."
2. See "II.C.4. Control Board
Check Procedure."
1. Clean.
2. Place in position.
1. Clean.
2. Increase water line size.
3. Replace with filter that has
larger flow rate.