COLD AIR!!

[mahjohn]

My model is: SL-550TR-IPI-E

Ok, so while I have another thread open on resolving why it's not lighting, what can I do about the wind tunnel of Cold Air... OMG!

In looking to repair it, I've looked to see why it's so cold, it's like having a window open in your house all the time. The vent pipe is straight out the back to a protective cage on the outside of the house, however, there is no damper, just a straight pipe, so when the fireplace is not lit, cold air rushes into the house.

Also, when the gas black pipe comes in on the lower left, the knockout (large oval) is gone and only the pipe is there. What material can I to plug this as cold air just rushes into the house.

Any ideas..thanks

 

[KeithO]

The combustion chamber of a dv stove/fireplace is supposed to be totally sealed except for the exhaust and fresh air connection at the flue. Since the venting connects only to the combustion chamber, there should not be a path out for cold air into the house.

The one common leak path is if there is a gap between the OD of the flue pipe to the ID of the wall thimble. I had about a 1/8" of a gap with mine and I sealed it with high temp Silicone sealer, which is sold at the stove section of my local Menards. It was black in color. You could check for leakage at the joints of the flue and caulk them if needed using the same stuff.

Other than that, do you lnow for a fact that the chase that the fireplace goes into is airtight ? It can leak air like any other part of the house if the home wrap was not taped or if there are a bunch of unsealed penetrations. Maybe some expanding foam is needed if you can tell air is coming in.

Where the gas pipe enters the shell of the fireplace should not have to be sealed, just where the gas connection enters the actual burn chamber, usually that spot is sealed with high temp silicone also to stop air leaks. If cold air is coming out that knockout, it suggests that the OD of the DV pipe is not making a good connection to the firebox. If the size of the pipe is not right it will never seal. I got a used stove with venting and the OD was 7" where it should have been closer to 6.3" so that pipe never fitted the stove right and cold air must have been pouring into the house through the resulting gap.

Bottom line, check everything and dont assume that what you have is the right material until you prove that it is and was installed properly.

 

[mahjohn]

I'll have a look at the vent, but understand what you mean by it should be self-contained, as any cold air coming into the firebox should not then enter the house.

The pipe....ugh. Not sure what these all look like, but imagine the setup is basically the same. Where that gas rigid black pipe comes into the firebox as best as I can tell there was a plate with a knockout. The installer has removed the entire plate to allow the pipe to come in. So instead of there being a small opening around the pipe to seal, there's a gaping hole maybe 2" x 4"....this is where my Cold Air is coming in.

My plan is to get some Rockwool (impervious to heat) and fill the opening with it.

thanks.

 

[KeithO]

Take a photo of the gas pipe. Usually a flexible convoluted pipe runs from the house black pipe to the inlet side of the gas valve. Then a second convoluted has pipe connects the outlet of the gas valve to the main burner.

Anywhere where a gas line enters the firebox it is usially a tight fit and sealed with silicone sealer (can withstand up to 600F)

 

[mahjohn]

Ok, here's a picture...see, hard rigid gas line incoming that changes over to flex. I expected to find a small hole like the one on the right....not the gaping wind tunnel I that exists.

If this were electrical, this would not be a code-compliant install. I doubt that it is for gas either.

 

[KeithO]

Looking at the photo, it looks like the black pipe is the gas feed from the house. Shutoff valve installed on the end of the black pipe. Then flex pipe to the gas valve. If thats not what it is, then Im pretty sure it wouldnt meet code. I have never seen anyone connect black pipe directly to the gas valve except on water heaters and furnaces where access is usually much better.

I dont understand how the gas connection should be causing any problems unless there is cold air leaking into the chase the fireplace is installed or the direct vent is not properly connected to the stove

 

[mahjohn]

The black pipe is the house feed. Shutoff valve, then flex line to the valve.

The air is ripping through the hole where the rigid gas line enters. This can only be from a poorly sealed exterior.

 

[mahjohn]

Final update, as the gas line enter outside of the firebox, I used Nashua Aluminum tape with a 200F rating. The temp on the foil after hours of operation (fireplace is fixed) is 112F.