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lindastracks
Oct 17, 2012, 06:12 AM
Hello Everyone
I am currently having a problem with my 2 stage electric forced air furnace. I have searched everywhere for information but to no avail. The furnace is probably a 1975 model... this is the information I have... Lear Siegler (Home Division) Model MEF65

Last winter while I was away there was a problem with it. A heat coil was changed and the limit control switch was changed. I was told at the time that after those changes were made it still did not work properly. As I will explain now.

This is the problem: The furnace starts up properly. Once it has attained the temperature it shuts down completely. Then the blower starts to expel the remaining heat an shuts down. About 2-4 minutes later the blower starts up again and shuts down.

So as to start with a clean slate... yesterday I changed the following:

1) The 4 sequencers were changed - in case one of them was defective and a heating element was staying on and causing the limit switch to turn on. The sequencers I installed are L150-40V

2) I changed the limit switch in case that was defective with an the same type 60T12 F110

3) I reprogrammed the thermostat which is an AUBE TH144 P 2H2C

4) I checked all the heat coils to see if they were still good.. and everything seems fine.

Guess what... it still doesn't work right

I am wondering if the limit switch that changed back in March is the right one... maybe the F110 should be higher?
I am wondering if the thermostat is defective and if so how do I check that without going into an expense.
I am wondering if there is another limit switch somewhere that I do not see (maybe it is inside heat coil section).

I have timed the on again.. it lasts about 22-23 seconds each time. The time span when it stops I about 28 seconds. If I do not lower the thermostat it will continue to do it.

Please help...
Thank you in advance

ma0641
Oct 18, 2012, 12:15 AM
Sounds like the fan on switch is set too low. Residual heat starts it up again. Try setting it up higher.