Evaporator Is Frozen Up - Hoshizaki KM-100A Service Manual

3. EVAPORATOR IS FROZEN UP

PROBLEM
[1] Freeze cycle a) Float Switch
time is too
long.
b) Inlet Water Valve
c) Control Board
[2] All ice formed a) Evaporator
on Evaporator
b) Water Supply Line 1. Water pressure too low.
does not fall
into bin in
c) Inlet Water Valve
harvest cycle.
d) Ambient and/or
e) Thermistor
f) Control Board
[3] Others a) Spray Tubes
b) Water System
c) Refrigerant
d) Expansion Valve
e) Hot Gas Solenoid
f) Water Supply Line
g) Water Filter
POSSIBLE CAUSE
water temperature
Valve
1. Leads shorted or
defective switch.
2. Float does not move
freely.
1. Diaphragm does not
close.
1. Defective.
1. Scaled up.
1. Dirty mesh filter or
orifice.
2. Diaphragm does not
close.
1. Too cool.
1. Out of position or loose
attachment.
1. Harvest Timer is set too
short.
2. Defective.
1. Clogged.
2. Out of position.
1. Dirty.
1. Undercharged.
1. Bulb out of position or
loose attachment.
2. Defective.
1. Coil winding opened.
2. Plunger does not move.
3. Wiring to Hot Gas
Valve.
1. Too small; requires 9.5
mm OD line dedicated
per machine.
1. Flow rate too small.
31
REMEDY
1. Check and replace.
2. Clean or replace.
1. Check for water leaks
with icemaker off.
Replace if necessary.
1. See "II. 3. [d] CONTROL
BOARD CHECK
PROCEDURE".
1. Clean.
1. Check and get
recommended pressure.
1. Clean.
2. Check for water leaks
with icemaker off.
Replace if necessary.
1. Increase temperature.
1. See "V. 14.
THERMISTOR".
1. Adjust longer, referring to
"II. 4. HARVEST
CONTROL -
THERMISTOR".
2. See "II. 3. [d] CONTROL
BOARD CHECK
PROCEDURE".
1. Clean.
2. Place in position.
1. Clean.
1. Check for leaks and
recharge.
1. Place in position.
2. Replace.
1. Replace.
2. Replace.
3. Check for loose
connection or open, and
replace.
1. Increase water supply line
size.
1. Replace with filter that
has larger flow rate.