Install manifold gauge set onto
suction and high side service valves.
Note: The procedures described below require the skills of a competent, EPA certied refrigeration technician.
Also required are a manifold gauge set, digital thermometer with thermocouple type probe,
pressure-temperature chart and various hand tools (wrenches, service valve rachet, etc.)
Refrigeration
Record suction line temperature,
4" from compressor.
Record discharge line temperature,
4 to 6" from compressor.
Compare super heat
and sub cooling.
Record liquid line temperature
before lter drier.
Is super heat within factory
specs of 10 – 12° F for freezers or
6 – 8° F for coolers?
Is liquid sub cooling
within factory specs
of 10 – 15° F?
Check and verify
refrigerant charge.
Not a refrigeration
system problem.
Is the evaporator ice covered?
See refrigerant
charging
procedure.
Charge OK?
See TXV
diagnostics.
See
“Walk-in Cooler or Freezer is Too Cold”
YES
NO
YES
OK
NOT
OK
NO
NO
YES
YES
Find and repair leak
and recharge system.