I have a Goodman GMP100-4 I had some problems with the upper limit switch, replaced that, but now it keeps getting thrown, When I set down and watched the furnace go through its steps I first noticed that the form of the burn was a little off, I did see a little dust and stuff in and around the burners so I broke out the vac and cleaned it up, but I'm having the yellow/orange flames, any ideas on what to do?

If I were called out to this job the first thing I would check is the inlet and out let gas pressures, then go from there.

If I were called out to this job the first thing I would check is the inlet and out let gas pressures, then go from there.

Is this something that I would be able to do as a consumer or would it be best to call in a pro? What does this consist of? Thanks for the Reply

Hmm... upper limit keeps tripping? Are you referring to one of the limits that surround the burners? Try this: observe operating sequence from start-up. If the flames start straying away from the cell holes when the blower starts, you probably have a leaky heat exchanger. If so, get a pro to evaluate unit ASAP.

Hmm...upper limit keeps tripping? Are you referring to one of the limits that surround the burners? Try this: observe operating sequence from start-up. If the flames start straying away from the cell holes when the blower starts, you probably have a leaky heat exchanger. If so, get a pro to evaluate unit ASAP.

That is exactly when it starts. Is the exchanger a fixable part or does it have to be replaced? Thanks for the Info.

It can't be repaired, and replacement may be economically impractical if the unit is out-of-warranty. Most have at least ten years, some twenty, and a few have limited lifetime. Even in-warranty, you may still be liable for labor expenses.

After swapping the heat exchanger the unit is back up and running. THANKS ALL!!