Why is My Gas Fireplace Creating Soot? - Ask the Expert Episode 251

Today’s question comes from Margie.

“Hey Dan, I have a ventless gas fireplace in my sunroom, which I loved at first. One, it has a thermostat, which I thought was great. However, it causes so much condensation, it is a mess. I purchased a portable dehumidifier. Two, it has created black soot all over everything. As a result, I have turned it off. I just know that if there is ever a storm, I will be able to turn it on and off and have heat in that room. Any suggestions?”

Yes, a ventless gas fireplace does cause condensation. If you have a problem with high humidity in your house and you get a ventless gas fireplace, it’s going to get worse. A dehumidifier is the right option if you want to keep using the fireplace.

Alternatively, if you do have a problem with dehumidity, you could probably try to run your air conditioner in dry mode if it has one. Otherwise, you could get a whole-home dehumidifier. I would really encourage you to mitigate excess humidity. It can cause all kinds of problems.

Now, for the soot issue, a ventless gas fireplace isn’t supposed to do that.

You need to have a tech come and check it.

It could be that the air-fuel ratio is off. The air intake shutters could be clogged. It could have clogged burner ports. Your burner logs could be out of place covering a burner unit too much.

Got more questions? Just ask in the comments below.

1 comment (view/add)
  • Clarence McGregor
    Clarence McGregor
    Posted on 3/22/2021

    I just watched this. I learned a lot, I guess that I was really ignorant before, oh yea you bet ya!

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