limit switch with the reset

[kellyp]

Hi,
I am having a problem with my Nordyne Gas Furnace. The porblem is the limit switch near the gas burner keeps tripping and I am wondering if you could tell me the causes and how to check each cause.

Thanks.

[Robert]

Hi,

Will need furnace model number, but can't help much on that. It is either a normal limit or a flame rollout limit.


They do fail and go bad sometimes and just need replacing.


However, it could be working and tripping for safety reasons.


To find out, you would need proper equipment and tools/meters to test with.


Thanks,
Robert

[kellyp]

Hi, Robert

My furnaces model # MGHA- 056ABFC- 05 with pilot light and I think the swithes part # is 626391. I do have the equipment to do the testing.

Here are some things I observed, when I reset the switch the furnace acts normal but sometimes the switch will trip again, sometimes I noticed that during the heating cycle the blower will shut off then come back on shut off and on again, and sometimes the furnace will act normal for 2 or 3 days and then the switch will trip again.

I hope this helps you narrow down the problem.
Thank, Pat.

[Robert]

Hi Pat,


I can't narrow it down without being there to test it. Along with having the equipment, you must also possess the knowledge and experience to use it and understand what it is telling you.


This goes hand in hand with what you are observing with experienced eyes.


Your furnace has the following:


Fan Switch # 626337

Limit Switch # 626336

Aux. Limit Switch # 626391

Limit Flame Rollout # 626352


All can be seen and ordered if needed through PayPal from here:

http://www.mobilehomerepair.com/NordyneGas.html



It could be any of those or a combo. It could be just a faulty switch with weakened contact points or a safety issue causing it to trip.


Because a wrong diagnosis here could be dangerous, best to let a Tech test it.


If it is just a faulty part, then you can DIY the replacement.


Thanks for inquiring,
Robert