TROUBLE SHOOTING GUIDE FOR UNITS WITH DX COOLING
9
Complaint
Symptoms
Probable Cause
Recommended Action
Ref.
Note
1. High temperature in
conditioned area.
Excessive load.
Check for excessive infiltration or
ventilation load. Check for
inadequate insulation of space.
2. Low temperature in
conditioned area.
Thermostat
controlling at too
low a temperature.
Reset or repair thermostat.
3. Bubbles in sight
glass.
Lack of refrigerant.
Repair leak and charge.
1
4. Compressor noisy
or operating at
abnormally low
discharge pressure or
abnormally high
suction pressure.
Leaky valves in
compressor.
Overhaul compressor.
4
D. Compressor runs
continuously.
5. Compressor fully or
partially unloaded, but
will not stop.
Solenoid stop valve
leaks.
Repair valve.
3
1. Compressor cuts
out on oil failure
protection control.
Lack of oil.
Add oil.
2. Compressor knocks.
Internal parts of
compressor broken.
Overhaul compressor.
a. Liquid "flood
back."
a. Check and adjust superheat.
Check for loose remote bulb on
section line.
5
3. Abnormally cold
suction line.
Compressor knocks.
b. Expansion valve
stuck in open
position.
b. Repair or replace expansion
valve.
E. Compressor is noisy.
4. Compressor jumps
on base.
Compressor loose
on base.
Tighten compressor hold down
bolts.
