stops heating

Questions about repairs and parts for Nordyne furnaces, air conditioners and heat pumps for manufactured homes including Intertherm, Mac and Miller brands. Click here for Nordyne parts.

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rwlyford
Posts: 5
Joined: Wed Dec 01, 2010 12:00 pm

Sat Mar 23, 2013 4:52 pm

I have a nordyne miller m1mb 077a bw The furnace starts and heats up and the blower runs, but before the house has reached the target temperature the furnace shuts down. once I saw a 1 blink yellow which says open limit switch. I replaced both switches and it ran for a long time. Then it started to do the same thing again. I replaced both switches again and it ran for a while longer, maybe 1 month. If i catch it when it fails the heater box feels real warm but i can put my hand on it and leave it there. If I leave the filter door off it seems to run ok When it stops there are no lights on the control panel.The ok red light is not on. I can restart the furnace by resetting the on/off switch on the furnace or turning the thermostat off heat and back to heat.Any ideas


jpingram5
Posts: 205
Joined: Sun Dec 05, 2010 5:34 pm
Location: Orefield, PA
Contact:

Sun Mar 24, 2013 8:32 am

Are you using the factory washable filter or are you using a different kind?
2009 Skyline Sunwood Premier 14 x 80

rwlyford
Posts: 5
Joined: Wed Dec 01, 2010 12:00 pm

Mon Mar 25, 2013 10:02 am

I am using the factory washable and have replaced with new.

jpingram5
Posts: 205
Joined: Sun Dec 05, 2010 5:34 pm
Location: Orefield, PA
Contact:

Mon Mar 25, 2013 2:49 pm

A new washable one or like the Pleated Style filters? If the return isn't pulling air through enough it could let the unit heat up more than normal which would cause the limit to constantly trip. Sounds like it since you say it runs fine without a filter on there. I was using the M1MB gas furnace before I switched it out and I had been using a Pleated style filter Merv 8 rating.
2009 Skyline Sunwood Premier 14 x 80

DaleM
Posts: 385
Joined: Wed Apr 07, 2010 10:07 am

Tue Mar 26, 2013 8:30 pm

How old is the furnace and is there an a-coil for air conditioning in the coil box?


rwlyford
Posts: 5
Joined: Wed Dec 01, 2010 12:00 pm

Thu Mar 28, 2013 1:53 pm

The furnace is probably 11-12 years old and yes it has an a coil in the lower compartment. Are you thinking it might be somewhat clogged? That thought has also gone thru my mind.Any way to clean without pulling the a frame? Could I use low pressure air to blow out and I have vacuumed the top surface as best as I could.

DaleM
Posts: 385
Joined: Wed Apr 07, 2010 10:07 am

Fri Mar 29, 2013 12:40 pm

That's what I was thinking.....dirty coil. I usually take a shop vac and a cut off chip brush to clean the coil the best I can without removing it from the system. As for the chip brush I cut the handle off damn near to where the wood handle goes into the metal bristel retainer then I trim the bristels back to about 3/4" long. Work it up and down in line with the fins to get the dirt loose.

rwlyford
Posts: 5
Joined: Wed Dec 01, 2010 12:00 pm

Thu Apr 04, 2013 5:46 am

I think you have nailed it. I have been thinking that my air flow at registers was getting to be lower. It happens slowly so you almost don't notice it. Will let you know when I have completed task.
Thanks for help.

jpingram5
Posts: 205
Joined: Sun Dec 05, 2010 5:34 pm
Location: Orefield, PA
Contact:

Thu Apr 04, 2013 5:54 am

Use some No Rinse Evaporator cleaner if you can get some. That stuff works great for me.
2009 Skyline Sunwood Premier 14 x 80

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