Hello all,
I have a Ducane forced air furnace. It was mfg. in 2001 and is set to propane. It has been fine for a while and we have a/c hooked up to it as well.

We started noticing that it was not running... go back and look and it needs the little tiny reset button pressed and it fires up no problem. But It seems that that may be the only way to keep this running. Someone looked at it briefly and said it was a quick fix and replaced some circular metal thingy LOL. That is attached by two screws.

Does this sound like anything you may have seen in the past? We were recommended to buy a new furnace but thought I would ask someone else.


Thanks for being that someone else!
Justin

((Someone looked at it briefly and said it was a quick fix and replaced some circular metal thingy LOL. That is attached by two screws.))

Possibly the manual reset high limit control for the furnace.
If after replacing this part troubles persist then something is causing the limit to trip and further service will be required.

Justin, there are a number of things that could be the problem, if you have to press a button to reset the furnace then it is most likely a limit switch as HVAC1000 stated, limit switches are set off by high temperature, a dirty filter will cause this to happen, it may be a roll out switch kicking off due to dirty burners ,so I would not be eager to replace the furnace since it is only seven years old, call a different service tech who is not just trying to make a sale, good luck, Mike

I agree with acetc and hvac1000. When it comes to a manual reset limit it should have been checked out closer, they trip for a reason HIGH TEMP. When it's a manual reset limit(they hardly ever go bad) and you have to reset it after the part has been changed its not the part. A manual reset is to let you know something major is wrong.

Thanks guys, I am going to attempt to look at this furnace a bit more on Sunday. It is in our convient store and the filter I think may have been messed up or hardley on for a while. So I am going to try to clean the whole system out. I could probley clean the fan assembly but is there anything else I should check is cleaned?

Today I noticed it was getting colder. We had the exahust fan on and its really cold up here in ny. So I went back and heard the furnice trying to start, so I clicked the reset button and after a few seconds it fires up with a nice blue flame. Walked away for about 5-10 minutes and come back and had to hit reset again.

If the evaporator coil(cooling coil) is dirty this will cause air flow restriction. If the system was being ran with out a filter you will need to clean the coil.

I cleaned the a-coil and so far so good... It hasn't had the problem yet... Ill give it a few days of monitoring though. Thanks a lot for the help guys.

Rooster-

Did that work? I am having the same trouble. The furnace has to be manually reset--sometimes 2-3 times per night, sometimes it will run fine for a week. How did you clean the coil?