Service manual

Section 7 Refrigeration System
Part No. 80-1206-3 7-9
2. Extremely Thin at Evaporator Outlet
There is no ice, or a considerable lack of ice formation at
the evaporator outlet.
Examples: No ice at all at the evaporator outlet, but ice
forms on the rest of the evaporator. Or, the ice at the
evaporator outlet reaches 1/8" to initiate a harvest, but
the rest of the evaporator already has
1/2" to 1" of ice formation.
Possible Causes: Water loss, low on refrigerant, starving
TXV, hot water supply, faulty water fill valve, float valve,
etc.
3. Extremely Thin at Evaporator Inlet
There is no ice, or a considerable lack of ice formation at
the evaporator inlet. Examples: The ice at the
evaporator outlet reaches 1/8" to initiate a harvest, but
there is no ice formation at all on the evaporator inlet.
Possible Causes: Insufficient water flow, flooding TXV,
leaking cool vapor valve, etc.
4. Spotty Ice Formation
There are small sections on the evaporator where there
is no ice formation. This could be a single corner, or a
single spot in the middle of the evaporator. Refer to
Evaporator Tubing Routing on the previous page to
determine your specific model’s tubing configuration.
This is generally caused by loss of heat transfer from the
tubing on the back side of the evaporator or insufficient
water flow.
5. No Ice Formation
The ice machine operates for an extended period, but
there is no ice formation at all on the evaporator.
Possible Causes: Water fill/float valve, water pump,
starving expansion valve, low refrigerant charge,
compressor, etc.
Important
The Q1400C & QDUALC model machines have left
and right expansion valves and separate evaporator
circuits. These circuits operate independently from
each other. Therefore, one may operate properly
while the other is malfunctioning.
Example: If the left expansion valve is starving, it
may not affect the ice formation pattern on the entire
right side of the evaporator.