Coleman 7956C856 Burner stays on, blower runs short bursts

[Wdeuerling]

I have a Coleman gas 7956C856. The burner is staying on and the blower only kicks on for a minute and waits a long time. I took things apart and vacuumed the A frame, and cleaned the inside of the heat exchanger.

The flame on the burner seems weak. It seems like the flame is not burning with enough intensity to to heat the exchanger. It builds up heat without the blower on, once the blower is on it cools down significantly. Cool air blows from the vents. This shuts the blower off and the cycle repeats.

Do I need a new burner kit, gas valve or gas jet (fitting)?

I'm looking for some advice on what to buy or clean.


Thanks

Bill

[hvac1000]

You may try cleaning the main orifice just in case it is partially plugged up causing a lack of flame size.

Other items like checking the gas pressure etc take special tools and knowledge. This is best left to a professional that know exactly what they are doing.

[Wdeuerling]

Thanks for the response. Do have recommendations of how to clean the orifice?

Thanks,

Bill

[hvac1000]

I would just use a small wire to make sure the orifice is open. Many times I remove it to make sure there is not a spider web hidding on the back side.

[Wdeuerling]

Thanks for the advice! I removed the orfice and found cobwebs. I cleaned it and the valve out. After reassembly, the furnace worked like a champ.

thank you so much. Have a great holiday season.

Bill