Troubleshooting Checklist for Domestic Refrigerators and Freezers (Continued)
What to look for and what to do
7. Unit runs continuously; tempera-
Refrigerant leaks or under-
The unit may tend to run normally but more frequently. The
ture too high (Continued)
evaporator becomes only partly covered with frost. The frost will
tend to build up nearest to the capillary tube while the section nearest
to the suction line will be free from frost. As leakage continues, the
frostline will move back across the evaporator. When the refrigerant
is entirely gone, no refrigeration will occur. Units with large
evaporators will not frost up unless the evaporator is mounted inside
of the box. Test for leaks with a halide leak detector. Recharge the
unit, if necessary.
Check the operation of the light switch, see that the light goes out as
the door is closed.
See that sufficient space is allowed for air circulation. Relocate or
reposition the unit, if possible.
Evaporator needs defrosting
Advise the user on defrosting instructions.
Give them a thorough cleaning. If worn they should be replaced.
Relocated the unit tin a location where the ambient temperature
ranges from 55 degrees to 95 degrees
On units so equipped, check the defroster heater circuit. See item 6.
Compressor suction valves
Ascertain whether the condenser gets warm, and check the current
sticks open or is obstructed by
drawn by the motor. If the condenser does not get warm and the
corrosion or dirt
current drawn is low, disassemble the compressor (open type) and
check the action of the suction valve
Compressor discharge valve
Connect the test gauge assembly, run the unit until the low-side
sticks open or is obstructed
pressure is normal. With an ear in close proximity to the compressor,
listen for a hissing sound of escaping gas past the discharge valve.
The low-side pressure gauge will rise, and the high side will drop
equally until both are the same. Clean out obstructions.
8. Unit runs too long; temperature
Check for any obstruction in the path of air circulation around the
condenser. Clean any dust accumulation.
On units so equipped, check to see that the fan blades are free to turn
and that the fan motor operates.
Clean seals around the door. Check closure of the door with a strip of
paper between the gasket and the cabinet at all points around the door.
The gasket should grip the paper tightly at all points.
Check for leakage and undercharge of the refrigerant. See item 7.
Warn the user against too frequent opening of the door, storage of hot
foods, heavy freezing loads, and other improper usage.
9. Unit operates on thermostat;
temperature too high
Check voltage ± 10 percent of rating.
See that the defrosting heater is turned off.
Determine that the starting relay does not stick closed. Follow the
manufacturer's instructions on methods of checking.