Evaporator Is Frozen Up - Hoshizaki KMS-1230MLH Service Manual

2. Evaporator is Frozen Up

Problem
[1]Freeze cycle time is
too long.
[]All ice formed on
evaporator does not
fall into bin in harvest
cycle.
[3]Other
Possible Cause
a) Float Switch
b) Fill or Harvest Water
Valve
c) Control Board
a) Evaporator
b) Water Supply Line
c) Water Filter System
d) Harvest Water Valve
e) Ambient and/or Water
Temperature
f) Liquid Line Valve
g) Thermistor
h) Control Board
a) Spray Tubes
b) Water System
c) Refrigerant
d) Expansion Valve
e) Hot Gas Valve
f) Water Supply Line
g) Water Filter
1. Leads short-circuit or
defective switch.
. Float does not move
freely.
1. Diaphragm does not
close.
1. Defective.
1. Scaled up.
1. Water pressure too
low.
1. Dirty/restricted.
1. Dirty mesh filter or
orifice.
. Diaphragm does not
close.
1. Too cool.
1. Continues to open in
harvest cycle.
1. Out of position or
loose attachment.
1. Defective.
1. Clogged.
. Out of position.
1. Dirty.
1. Undercharged.
1. Bulb out of position or
loose attachment.
. Defective.
1. Coil winding opened.
. Plunger does not
move.
3. Wiring to hot gas
valve.
1. Too small; requires
1/" OD line dedicated
per machine.
1. Flow rate too small.
37
Remedy
1. Check and replace.
. Clean or replace.
1. Check for water leaks.
1. See "II.C.4. Control Board
Check Procedure".
1. Clean.
1. Check and get
recommended pressure.
1. Replace filter.
1. Clean.
. Check for water leaks.
1. Increase temperature.
1. Check operation in harvest
cycle and replace.
1. See "V.C.6. Removal
and Replacement of
Thermistor."
1. See "II.C.4. Control Board
Check Procedure".
1. Clean.
. Place in position.
1. Clean.
1. Check for leaks and
recharge.
1. Place in position.
. Replace.
1. Replace.
. Replace.
3. Check for loose
connection or open, and
replace.
1. Increase water line size.
1. Replace with filter that has
larger flow rate.