Hoshizaki KM-901MAH Service Manual page 64

Problem
[1]Freeze cycle time is
too long. (continued)
[2]All ice formed on
evaporator does not
fall into bin in harvest
cycle.
Possible Cause
f) Thermistor
g) Refrigerant
h) Expansion Valve
i) Control Board
a) Evaporator
b) Ambient and/or Water
Temperature
c) Water Supply Line
d) Water System
e) Inlet Water Valve
f) Spray Tubes
g) Thermistor
h) Hot Gas Valve
i) Expansion Valve
j) Liquid Line Valve
(if applicable)
k) Control Board
1. Disconnected, loose,
or defective.
1. Low charge.
1. Bulb loose.
2. Operating erratically.
1. Defective.
1. Scaled up.
2. Damaged.
1. Too cool.
1. Water pressure too
low.
1. Water supply line
too small; requires
3/8" OD line dedicated
per machine.
2. Water filter clogged or
flow rate too small.
1. Dirty mesh filter or
orifice.
2. Diaphragm does not
close.
1. Dirty.
2. Out of position.
1. Disconnected, loose,
or defective.
1. Coil winding open.
2. Plunger does not
move.
3. Wiring to hot gas
valve.
1. Bulb loose.
2. Operating erratically.
1. Continues to open in
harvest cycle.
1. Harvest timer is set
too short.
2. Defective.
64
Remedy
1. Connect, secure, check.
See "V.L. Removal
and Replacement of
Thermistor."
1. Check for leaks. Recover,
repair, evacuate, and
recharge.
1. Secure bulb.
2. Check and replace.
1. See "IV.B. Control Board
Check."
1. Clean.
2. Replace.
1. Increase temperature.
1. Check and get
recommended pressure.
1. Increase water line size.
2. Replace filter or install a
higher flow rate filter.
1. Clean.
2. Check for water leaks with
icemaker off.
1. Clean.
2. Place in position.
1. Connect, secure, check.
See "V.L. Removal
and Replacement of
Thermistor."
1. Replace.
2. Replace.
3. Check for loose
connection or open, and
replace.
1. Secure bulb.
2. Check and replace.
1. Check operation in harvest
cycle and replace.
1. Adjust longer, referring to
"II.C.3.b) Harvest Timer
(S4 dip switch 1 & 2)."
2. See "IV.B. Control Board
Check."