Lennox L Series

[AllTemp]

Have had similar failures on two LGA360 systems with the indoor fan blower motor mounts.
http://www.alltemp-hvac.com/blower.jpg
The fram for the mount has cracked and allowed the motor mounts to rock and break itself apart.

Lennox tells me fan is cycle on and off cauing this or high static pressure... I say Lennox doesn't want to own up to a design flaw... Sheet Meal bracing in a 10 HP mtor, come on... The thing should be able to take normal system cycling, they say leave the blower on if possible...

In the picture you can see the double smaller screws in the bottom of the frame these are the ones that have sgtripped and the top of the fram in the corners broke...

[mike4hvac]

Just hotwire the fans to run 24/7/365. Its better to change the Blower Moter once in awhile then to replace all that. We do it all the time with our RTU's.

[rubobornot]

How could it be high static pressure, I thought the blower would move less air at a high static pressure and more at a low static pressure due to less resistance to air flow. The company that I work for had the same problem on some L series units, replace almost all the blower mounting brackets.

[AllTemp]

Typical of Lennox to state there are no issues with the blower brackets.

This is the second system I have worked on in two years.

Parts came in today and the Pivot Frame is short, required us to spend hours on the phoen back and forth the learn there had been a revison. I think they mfg these too short and to save the parts re mfg a cheaper fix a flanged C channel upside down, flimbsy to give the heigth back...

Anyone working on a L series, Fxxxxck the fricken smal 1/-20 screw that hold the motor frame, slie the blower assembly out you can get under the blower and reach up and install some back up nuts on some grade 5 minmum 5/16 seraded flanged bolts, you'll save some heart ache later..