Diagnostic Charts; No Ice Production - Hoshizaki KM-251BAH Service Manual

disconnect the float switch by unplugging the harness from the K5 connector. The unit
should switch out of the freeze cycle.
Note: At this point, after the initial freeze cycle and every 10th cycle thereafter, LEDs
1, 3, and 2 come on, the compressor continues to run, the hot gas valve opens
and the fan motor de-energizes. The pump motor stops for 2 seconds. The pump
motor restarts and runs for 10 seconds.
Diagnosis: If the evaporator is not cold, check to see if the hot gas valve is still open
or if the expansion valve is not opening properly, if the harvest water valve or harvest
valves relay is stuck open (the freeze water valve will cycle on and off during freeze), if
there are improper unit pressures, or an inoperative compressor. If the unit remains in
freeze with the float switch removed, replace the board.
Note: Normal freeze cycle will last 20 to 40 minutes depending on model and
conditions. Cycle times and pressures should follow performance data provided
in this manual.
6) Normal Harvest Cycle – same as the initial harvest cycle – Return to step 4.
Note: Unit continues to cycle until bin control is satisfied or power is switched OFF. The
unit always restarts at the 1 minute fill cycle.
B. Diagnostic Charts

1. No Ice Production

Problem
[1] The icemaker will not
start.
Possible Cause
a) Power Supply
b) Control Switch
c) Fuse (internal)
d) Bin Control
e) High Pressure Control 1. Bad contacts.
1. Off (breaker tripped or
fuse blown).
2. Loose connection.
3. Bad contacts.
4. Voltage too high or too
low.
1. OFF position.
2. Bad contacts.
1. Blown.
1. Tripped with bin filled
with ice.
2. Improperly activated.
2. Dirty air filter or
condenser.
3. Ambient or condenser
water temperature too
warm.
4. Refrigerant
overcharged.
23
Remedy
1. Reset breaker or replace
fuse.
2. Tighten.
3. Check for continuity and
replace.
4. Check and get
recommended voltage.
1. Move to ICE position.
2. Check for continuity and
replace.
1. Check for short circuit and
replace.
1. Remove ice.
2. Check for proper position
and movement.
1. Check for continuity and
replace.
2. Clean.
3. Reduce temperature.
4. Recharge.