G&F Manufacturing R-410A, Service Manual

Page: 7 / 17

Low Refrigerant Pressure
Low pressure cut out is 37 pounds cut in is 80 pounds. Unless the defrost sensor is way out of
calibration, you should never see this code because of low ambient temperatures. You should
only see this code if there is a refrigerant leak. Find and repair the leak.
Water Flow Lockout
High Refrigerant pressure is 540 cut in is 360. This error code is almost always a lack of
water flow, so check everything under “No Flow” before putting on gauges or condemning
High Pressure switch.
Evaporator Sensor Malfunction
This is a 10k sensor. If it is open or outside its range you’ll get this error. Check connections
before replacing.
Water Sensor Malfunction
This is also a 10k sensor. If it is open or outside of its range you’ll get this error. Check
connections before replacing.
ATTENTION
:
This is a standard refrigeration system and most diagnostics are the same as air conditioners.
However, you must keep in mind that the Heat Exchanger is the condenser and the large air
coil around unit is the evaporator. The system consists of a compressor, water-cooled
condenser, TXV, and air heated evaporator.
ATTENTION
:
Diagnosing the refrigeration system is something all A/C technicians should know. However,
there are a few points we would like to point out.
Page 7