Filter
Top Products
Compressor runs, but evaporator does not
1. Faulty blower
motor or broken wire
connection
Evaporator coil probably frozen•
Shut off power to condensing unit•
Call a CERTIFIED HVAC service technician for repair•
2. Defective low
pressure switch not
shutting compressor off
when pressure drops
Compressor would continue to run when thermostat •
is satisfied and shuts blower and solenoid off. When
space warms up to set point, blower starts and the
system runs normally.
Prolonged running without refrigerant flow will •
damage or destroy compressor. If this condition
exists, call a CERTIFIED HVAC service technician.
Compressor short cycles, which is different from running intermittently
1. System pressure
controls defective.
Call a CERTIFIED HVAC service technician to verify and
repair.
2. System low on
refrigerant.
Observe for flashing in refrigerant sight glass located
in1/4”coppertubeatcondensingunit.Ifashingwith
bubbles, call a CERTIFIED HVAC service technician for
leak location, repair, and adding refrigerant.
3. Condenser fan motor
defective
Fan does not run with compressor. •
¼” copper tube at sight glass – very hot, compressor •
very hot, runs short time, shuts off.
Shut power off to condensing unit•
Call a CERTIFIED HVAC service technician for repair.•
4. Compressor starting
components defective.
Compressor very hot and hums when trying to start.•
Shut power off to condensing unit.•
Call a CERTIFIED HVAC service technician.•
Evaporator coil freezes
1. Air filter, if
equipped, dirty
Clean or replace filter
2. Evaporatorcoiland/
or blower dirty
Clean coil and blower
3. Thermostat set point
too low.
Set point should not be lower than 50°. If so, increase to
above 50°
4. System low on
refrigerant
Checkrefrigerant“sightglass”in1/4”tubing.Check
for bubbles after system has run for several minutes. If
bubbles present, call a CERTIFIED HVAC service technican.
If sight is clear of bubbles, refrigerant level is OK.
-26-