Gas and Oil Home Heating Furnaces - Goodman Furnace Problem

Hope this is not a redundant posting. I have a Goodman 93% efficient furnace installed in my home. Here is situation:

1) Furnace begins to operate normally but during the heating cycle (10 - 15 minutes) the burners go out and the #4 LED code begins flashing. Circulator blower continues to run.

2) After several minutes the LED indicator switches to a continous mode(normal operation), the burners reignite and the furnace begins operating again.

3) This process will continue until desired temperature is reached in the home and then the furnace shuts off normally.

I assume that this is not the proper operating process for the furnace and was curious if there is a simple diagnostic/fix I could perform before speaking with a Goodman tech.

Any advice is much appreciated!

Sorry, I don't know what a 4 code indicates. I suspect it is a high limit. You can try increasing the fan speed. Make sure all vents (supply & return) are open & not blocked or otherwise restricted. Make sure the air filter is clean. If you have a pleated air filter, especially a 3M, pull it out & try the furnace. If it works ok without the filter, get a cheap glass fiber filter. You can also check the blower wheel to make sure it is clean.

Thanks for the suggestions Grady. I will give these a try tomorrow when I return home.

I looked at the owners manual for the furnace and a #4 LED error is a "Limit switch/Aux Limit swith" error.

Another item I did not consider is that I have had some drywall repairs the last week and there has been lots of dust. Perhaps this is contributing to the limit switch error.

Ridge

There is a very good chance the filter is quite dirty. Be sure to check the blower wheel when you change the filter.

Grady, I have followed all of your recommendations (cleaned blower fan, increased motor speed, replaced filter with a cheap glass fiber filter) and the furnace seems to be back to working normally.

Thanks again for your response with these steps!

If it was doing OK last year, I'd put the blower speed back the way it was. Obviously, if you start having trouble again, change it to the higher speed. Was the old filter really dirty, particularly with dry wall dust?

Grady, the filter was extremely dirty. I think the higher grade filter was really reducing the air flow as well. I hadn't noticed, but when I put the cheaper glass fiber filter in all vents showed a large jump in flow. This is before I moved the fan speed to the higher setting. I plan to tweak with the filters, dampers on the vents and the fan speed to get the appropriate balance of air flow. I still have a few more drywall repairs to make that will continue to dust up things so I will wait until I can get that finished before adjusting the fan speed.

Thanks again.

Ridge

When you are doing the drywall, it might be a good idea to use the more restrictive filter because they do a better job of actually filtering the air. You will have to change it more often but you certainly don't want that drywall dust getting into the blower & A/C evaporator (if you have A/C). It sounds like I'm backtracking but since you've figured out the cause you can take steps to prevent the same problem & at the same time prevent other problems caused by the drywall dust.