Air Handlers
21
6 Common Malfunction and Elimination
If the unit doesn’t run normally, please check the following items before ask for
service.
Phenomenon
Reason
Treatment
The unit can not be
activated.
The unit doesn’t connect with
power supply.
Connect with power
supply.
Low voltage.
Check if circuit voltage
is within rated scope.
Fuse broken or breaker trips
off.
Replace fuse or
connect breaker.
The unit operates but
stops immediately.
Air inlet/outlet of indoor unit is
blocked.
Remove obstacles.
Abnormal cooling or
heating.
Air inlet/outlet of indoor unit is
blocked.
Remove obstacles.
Inappropriate temperature
setting.
Adjust setting at
thermostat.
Doors or windows are
opened.
Close the door or
windows.
Direct sunshine.
Draw curtain or louver.
Too much heat source in the
room.
Reduce heat source.
Filter screen is blocked by
dirt.
Clean the filter.
NOTE:
If reasons are still unclear after checking above items, please contact
LENNOX
service center and show phenomena and models.