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M1BB 086A BW gas furnace Wont Start

Posted: Sun Feb 14, 2010 10:25 am
by dblacks
Miller/nordyne M1BB 086A BW

Turn termostat on and nothing happens, power to the furnace but no noises f anythign trying to start and no led lights on the UE 1018 hot surface ignightor which should be flashing something. Tells me the board must be bad

what are your thoughts???

Thanks

Dana

Re: M1BB 086A BW gas furnace Wont Start

Posted: Sun Feb 14, 2010 12:06 pm
by dblacks
After taking the cover off where the coil and transformer are I found the 3a fuse on the red wire going coming from the thermastat to the transformer was blown, changed it turned power on and the thermastat made a cranckling noise like it fried itself and the fuse didnt blow but got very warm and the transformer 621807 got very very warm

Re: M1BB 086A BW gas furnace Wont Start

Posted: Mon Feb 15, 2010 9:13 am
by dblacks
any deas?

Re: M1BB 086A BW gas furnace Wont Start

Posted: Tue Feb 16, 2010 7:56 pm
by Robert
There is a short somewhere in the low voltage circuit. Get an hvac tech out to locate it for safety as it is a fire hazard.




Thanks,
Robert

Re: M1BB 086A BW gas furnace Wont Start

Posted: Tue Feb 16, 2010 10:51 pm
by dblacks
i got my tester back frm my buddy and tested everything, turned out to be the centrifical switch in the motor shorted so I had to get a new motor, motor would run when I bypassed the modul thou so it was just the switch coming from the module, thanks anyways.


Odd thing is the short blew the fuse but also blue the transformer and the cheapo T-Stat.

Re: M1BB 086A BW gas furnace Wont Start

Posted: Wed Feb 17, 2010 1:13 am
by Robert
Glad you found it. T-Stat and xfmr probably got hot before fuse blew. Second time they finished off before fuse blew.


Take care and best wishes,
Robert