Evaporator Is Frozen Up - Hoshizaki KM-150BAF Service Manual

2. EVAPORATOR IS FROZEN UP

PROBLEM
[1] Freeze cycle a) Float Switch
time is too
long.
b) Water Solenoid
Valve
c) Controller Board
[2] All ice formed a) Evaporator
on Evaporator b) Water Supply Line
does not fall
into bin in c) Water Solenoid
harvest cycle. Valve
d) Ambient and/or
water temperature
e) Thermistor
f) Controller Board
[3] Others a) Spray Tubes
b) Water System
c) Refrigerant
d) Expansion Valve
e) Hot Gas Solenoid
Valve
f) Water Supply Line
g) Water Filter
POSSIBLE CAUSE
1. Leads short-circuit or
defective switch.
2. Float does not move freely.
1. Diaphragm does not close.
1. Defective.
1. Scaled up.
1. Water pressure too low.
1. Dirty mesh filter or orifice.
2. Diaphragm does not close.
1. Too cool.
1. Out of position or loose
attachment.
1. Defrost 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 3/8" OD 1. Increase water supply
line dedicated per machine
1. Flow rate too small.
35
REMEDY
1. Check and replace.
2. Clean or replace.
1. Check for water leaks
with icemaker off.
1. See "II.2. [ e ] CHECKING
CONTROLLER BOARD."
1. Clean.
1. Check and get
recommended pressure.
1. Clean.
2. Check for water leaks
with icemaker off.
1. Increase temperature.
1. See "V. 10. REMOVAL
AND REPLACEMENT
OF THERMISTOR."
1. Adjust longer, referring
to "II. 2. [d] CONTROLS
AND ADJUSTMENTS,
2) Defrost Timer."
2. See "II. 2. [ e ] CHECKING
CONTROLLER BOARD."
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.
line size.
1. Replace with filter with
larger flow rate.