Lennox air handler fan running bad?
#1
12-08-21, 02:50 PM
Lennox air handler fan running bad?
Hi
I have a Lennox CBA27UHE-042 indoor air handler. When the AC is running the fan continually blows fast/slow/fast/slow until the desired temp is reached & the unit turns off. The fast/slow cycle is best described as like trying to start a car on a very cold winter morning with the engine trying to turn over. You can feel the difference in the amount of air being pushed through the vents, normal amount of air then not much then normal then not much & so on. The fast slow cycle is each a few seconds long. This cycle is non stop as I said above until the requested temp is met. When the panel that accesses the fan was removed the issue all but goes away but as soon as the panel is put back in place the issue starts again. Any ideas on what might be going on? Thanks
I have a Lennox CBA27UHE-042 indoor air handler. When the AC is running the fan continually blows fast/slow/fast/slow until the desired temp is reached & the unit turns off. The fast/slow cycle is best described as like trying to start a car on a very cold winter morning with the engine trying to turn over. You can feel the difference in the amount of air being pushed through the vents, normal amount of air then not much then normal then not much & so on. The fast slow cycle is each a few seconds long. This cycle is non stop as I said above until the requested temp is met. When the panel that accesses the fan was removed the issue all but goes away but as soon as the panel is put back in place the issue starts again. Any ideas on what might be going on? Thanks
Last edited by PJmax; 12-08-21 at 04:07 PM. Reason: corrected model number
#2
12-08-21, 03:17 PM
Group Moderator
Not sure if the model number is correct. I didn't locate the manual for it.
Do you have an ECM (electronic) motor ?
Some of those are setup to monitor static air pressure and change blower speed accordingly.
A severely clogged filter or system restriction could cause that problem.
Do you have an ECM (electronic) motor ?
Some of those are setup to monitor static air pressure and change blower speed accordingly.
A severely clogged filter or system restriction could cause that problem.
#3
12-08-21, 03:30 PM
Hi Pjmax
I don't know if I have an ECM motor. I rechecked the model # & the first letter should have been a C. Model CBA27UHE-042 My bad.
I replaced the filter but that did not help. Thanks
I don't know if I have an ECM motor. I rechecked the model # & the first letter should have been a C. Model CBA27UHE-042 My bad.
I replaced the filter but that did not help. Thanks
#4
12-08-21, 04:37 PM
Group Moderator
Yes.... that unit uses an electronically controlled motor. They can be expensive to replace and work on.
That unit looks to be a fairly new model and should carry a five year warranty.
I'd call for warranty service.
Lennox manual - pdf
That unit looks to be a fairly new model and should carry a five year warranty.
I'd call for warranty service.
Lennox manual - pdf
