Leaking vent pipe joints, single wall.

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donnie_19

New Member
Jan 13, 2013
5
I acquired the wood burning furnace when we purchased the house 10 years ago. So far everything has been fine. It was warm for several days so I cleaned the flue pipe and vacuumed out. I now have a few of the single wall elbows and joints leaking. Is there a product I an apply to the leaking areas that will seal them back up.
 

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You shouldn't need to seal the joints. once the chimney heats up, the negative draft should be pulling air in through those cracks. depending on how cold the chimney is, it could take a while.
 
Something not drawing correctly. Had the fire going for 8 hours and still leaking ever time the fan kicks on.
 
You shouldn't have galvanized pipe for the flue. At a certain temp, the galvanized coating burns off and creates a poisonous gas. It looks as though it's condensation leaking out of the joints. Are you seeing smoke when it leaks or liquid? If it's leaking smoke when the fan runs (combustion fan?) then there's an obstruction in the system. If it's liquid (condensation) that's leaking, your gasses are too cool. What size is your chimney, and what furnace are you burning?
 
Something not drawing correctly. Had the fire going for 8 hours and still leaking ever time the fan kicks on.

What fan? What kind of furnace?
 
Don't think its galvanized just old. This set up was installed when we bought the house. I have put the fire out and letting everything cool down and take this bottom section apart for inspection. Don't see a brand name on the unit.
The joints were only leaking smoke no liquid. The small fan at the bottom of the picture runs when it needs heat. This caused most of the smoke. I am sure still smoking when main blower kicks on.
 

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I'm 100% sure that's galvanized pipe. The dull areas are where the coating has burned away. Galvanized pipe usually isn't as thick as black pipe. Check your chimney cap if you have one to see if it's obstructed. The smoke could either be what's within the pipe joints getting hot and burning, or the chimney is partially blocked. With an ample draft, there should be no smoke.
 
Ok on the galvanized but its been installed for over 10 years. I had the cap off last week and cleaned. Unfortunately there is ice on the roof today so going to attempt to disassemble from inside and clean with my brush and shop vac.
Should I change the piping out?
 
I would change the pipe to black stove pipe as suggested. You don't have a damper or anything in the pipe do you? Everyone else's suggestions are spot on as far as draft. If all has worked well for 10 years then there must be something obstructing the chimney. There should be sufficient draft to pull the smoke up and any little air leaks in the smoke pipe should be just pulling air in and exit the chimney with the smoke.

TS
 
I would change the pipe to black stove pipe as suggested. You don't have a damper or anything in the pipe do you? Everyone else's suggestions are spot on as far as draft. If all has worked well for 10 years then there must be something obstructing the chimney. There should be sufficient draft to pull the smoke up and any little air leaks in the smoke pipe should be just pulling air in and exit the chimney with the smoke.

TS
Changed out all the pipe today with new 8" black stove pipe. Old stove pipe fell out in pieces so good time to change. There was a damper and I put it back in the new pipe and made sure it is functioning correctly. Shined a flashlight up the flue pipe and didn't see any obstructions. Lit a new fire, made sure the damper was wide open and same thing, smoke coming out door and around a few of the seams of the new pipe. That leaves the flue cap causing a restriction. Got dark on me and a little ice on the roof today so will climb up tomorrow and check the cap. Thanks for all the suggestions.
 
Let us know donnie, if the cap is clean and all looks good in the flue, I'd consider lighting some newspaper in the back of the firebox before lighting a wood fire. The newspaper will give a good blast of heat to get the draft pulling the smoke up the chimney well.

TS
 
It's a good thing you replaced that pipe, could've been a disaster. Some chimney's require priming like Taylor mentioned, alot of times it's exterior chimneys which run a little cooler. Also if the chimney has a cleanout or tee, make sure it's capped or sealed. Sometimes it's something simple that's been missed.
 
If your flue cap has a screen on it, those things are vulnerable to choking themselves off.

If you find that to be the case, I'd try to just get the screen off rather than trying to clean it. Some might not like to do that, but I've never had any birds make their way down our chimney yet.

And please be careful on the roof - I had a way too close call on mine last fall, it was one of the tipping points for deciding on my recent boiler swap.
 
That would be a Royall wood furnace. Its a very well constructed unit. They still make them and sell parts. Located in Reedsburg, Wi. Kevin
 
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