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Chimney & Fireplaces/venting issue on 2 sides direct vent gas fireplace


I have a 2-sided direct vent gas fireplace that has venting issues where we get a gas smell and increased co2 reading (2 pts per million) when we turn it on. How can this be corrected and would a vent hood help?

Hello Mike, 1st a direct vent system should be sealed with glass between you and the fire and if it is the vents maybe clogged or what might be happening is you are getting Negative Pressure in your home (house stack effect) that is hot air rising in your home (and getting out through the attic vents, doors, lights, another fireplace (is it closed?)) your house is a better chimney than your chimney. Also kitchen/bathroom exhaust fans, clothes dryers, Radon systems and the boiler/furnace all take house air out of the house (mechanical negative pressure) your house needs make up air, perhaps an open window in the  where the unit is until it gets going? Or stop the air from getting out the attic and other area’s. has the gas been tuned?
Trail and error until you get this fireplace to work for you, maybe close off the room from the rest of the house to use it (close doors)
Or it could be dirty? I would have a local Certified Chimney Sweep (, there you can look up by zip code to find one near you) take a first hand look at what you have.

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James Ball


I am a chimney sweep with over 22 years of experience, CSIA certified and member of the NCSG, I can answer questions about smoky fire places, wood stoves, and heating units (boiler and furnace chimneys) do you need a relining? A cap? And much more


over 22 years

Chimney Safety Institute of America, National Chimney Sweep Guild

CSIA (Chimney Safety Institute of America) certified

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