Evaporator Is Frozen Up - Hoshizaki KM-515MAH Service Manual

Problem
[8] All components
run, but no ice is
produced.

2. Evaporator is Frozen Up

Problem
[1]Freeze cycle time is
too long.
Possible Cause
a) Refrigerant
b) Compressor
c) Hot Gas Valve
d) Line Valve
(if applicable)
e) Inlet Water Valve
f) Expansion Valve
g) Headmaster (C.P.R.)
(remote air-cooled
model only)
h) Water Supply Line
(water-cooled model
only)
i) Water Regulating Valve
(water-cooled model
only)
Possible Cause
a) Float Switch
b) Inlet Water Valve
c) Control Board
d) Water Pump
e) Spray Tubes
f) Evaporator
g) Expansion Valve
1. Low charge.
2. Air or moisture
trapped.
1. Defective valve.
1. Continues to open in
freeze cycle.
1. Continues to close in
freeze cycle.
1. Water valve is wide
open during freeze.
1. Operating erratically.
1. Not operating properly
and liquid line
temperature too warm.
1. Condenser water
pressure too low or
off and high pressure
control opens and
closes frequently.
1. Set too high.
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.
38
Remedy
1. Check for leaks and
recharge.
2. Replace drier and
recharge.
1. Replace.
1. Check and replace.
1. Check and replace.
1. Check for water leaks with
icemaker off.
1. Check and replace.
1. Replace headmaster.
1. Check and get
recommended pressure.
1. Adjust or replace. See
"V.G. Adjustment of Water
Regulating Valve."
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.