Water in chimney?

[johnha]

Brother called me with an issue just now. He went to brush his insulated triple wall stainless chimney this afternoon and when he pulled the cap off the cleanoff, about a half cup of water fell out. As he brushed, the creosote that came down was also wet with water.

They had a little snow Friday but nothing much for a week before that. He runs a brush up the length monthly during the burning season. 25'

Any ideas as to why entertained. Thanks.

 

[mga]

could be condensation. does he keep the damper closed when not burning wood? heat from the house could be traveling up the flue and the warm air condensing.

was the flue insulated?

is the chimney in the center of the house or on an outside wall?

 

[johnha]

Outside wall. Goes from the stove out through the wall and then straight up about 25'. I was thinking condensation myself but that seemed like an awful lot of water he was describing.

I don't believe there is a flue in his system. Black pipe from stove to wall collar.

 

[mga]

again, does he keep the damper open when not burning a fire?

the reason i asked where the chimney was is because a chimney in the middle of a house stays warm and has less issues. a chimney on the outside wall gets cold from the air temps. this is one reason why they recommend sleeving an "outside" chimney with insulated pipe.

even his chimney with just clay(?) tiles will 'sweat" if enough heat rises and the tiles are cold.

secondly, if he has an area on his cap that will hold water, he should do something about that.

 

[kevin j]

Condensation of water vapor i the exhaust. Water from the wood, but mostly form combustion of any hydro carbon fuel gives off a lot of water vapor. Liek car exhausts... usually it's hot enough to stay vapor but with low burn and cold chimney it can condense.
I have a small airtight stove. Had the top of flue actually ice up one time. Also had the top foot of stainless where it sticks out of the masonry part condense up and block down with a thin creosote membrane to a draft hole only about an inch in diameter. I made a double cone shaped thing and insulated the stainless up the the very top. Keeps it much warmer, no more problems in 10 years.

Chimneys on the outside are prone to being cold. Can you box it in somehow? How cold does it get there?

 

[johnha]

oops, sorry. No damper.

He's in suburban Harrisburg, PA. Our winter in SE Pennsylvania has been milder than usual.

 

[mga]

oops, sorry. No damper.

He's in suburban Harrisburg, PA. Our winter in SE Pennsylvania has been milder than usual.

i'm going to guess the warm air he's losing because he doesn't have a damper is causing the moisture in the chimney. it doesn't have to be freezing out, just colder than the air escaping.

 

[Tesen]

I had a similar problem a few months back, I use an Exhausto fan always set on low to help the flue draft (old house, sometimes suffers from stack effect, so we just leave it on low to draft properly, so we do not wake up dead one day). Anyway I was planning on replacing firebrick so I loaded it with the intent for it to go out by morning. I replaced the firebrick, cleaned the furnace out, got it all prepped to be lit, then my bro inlaw called. Long story short, my wife and I went out with bro inlaw and his GF for the day, gas furnace keeping the house at a nice 58F (my cats were warm enough ).

I get home, I realize I left the exhaust fan on and was like: "oh, what a waste of electricity! doh!" it is about 9pm, so I turn it off and think, "ohhh to hell with this, I'll light it in the morning." I get up, turn the fan on (or so I thought) and light it, go up stairs to grab a cup of coffee and the lower smoke alarm goes off. I am like, "ought-oh! did I forget to close the feed door?!?!?" I go down, smoke everywhere! I race for the basement door, open it grab the water hose while I am at it and analyze the situation, nope, no fire door open, back drafting badly! I close the dampers, including the intake on the draft fan, now it is still smoking from the feed door (never seals airtight, hotblasts suck like that) and around the stove pipe leading to the tripple wall which goes outside. My first thought is, "okay, must be massive stack effect issue and the exhaust fan is not working." so I leave the basement door open, open more basement windows. The smoke decreases basically to nothing and what is still coming out of the stove pipe is blown out the other windows quickly.

I finally find my multi-meter, the circuit is not drawing crap for the exhaust fan. Should be about an amp or so, nada, zero. I am thinking, "ohhh great, did a diode blow? Cap?" After doing some additional checking I come to the conlusion it is blocked. Getting to the top of my flue requires a bucket truck currently, so my bro inlaw brings one over, he doesn't believe me that it could be blocked. Sure enough, we get up there nice ice block froze around the fan blades causing the fan to stall out.

So yeah, you can get condensation in your flue and you also can clog your exhaust fans if you use them. This springs project (once my Son is born) is to wire up a voltage and current monitor for the circuit, so when we do light up, we can still the exhaust fan is running before ever striking a match. I also plan to add a backup battery supply to the exhaust fan and my hotblast blowers, that way if I lose juice we can still starm warm and safe. Actually my fire works well without the exhaust fan, but there was this one situation where we were burning coal that we got some massive backdrafting issues, it was cheap ass coal (read: free) so to be safer than sorry, I swore I'd always keep the flow going the right way With the little one coming very soon (next week or so) anything that allows us to heat cheap and keeps us safe is a must have!

Sorry kind of a long story, but I am in that mood tonight

Tes

 

[A. Stanton]

I had a similar problem a few months back, I use an Exhausto fan always set on low to help the flue draft (old house, sometimes suffers from stack effect, so we just leave it on low to draft properly, so we do not wake up dead one day). Anyway I was planning on replacing firebrick so I loaded it with the intent for it to go out by morning. I replaced the firebrick, cleaned the furnace out, got it all prepped to be lit, then my bro inlaw called. Long story short, my wife and I went out with bro inlaw and his GF for the day, gas furnace keeping the house at a nice 58F (my cats were warm enough ).

I get home, I realize I left the exhaust fan on and was like: "oh, what a waste of electricity! doh!" it is about 9pm, so I turn it off and think, "ohhh to hell with this, I'll light it in the morning." I get up, turn the fan on (or so I thought) and light it, go up stairs to grab a cup of coffee and the lower smoke alarm goes off. I am like, "ought-oh! did I forget to close the feed door?!?!?" I go down, smoke everywhere! I race for the basement door, open it grab the water hose while I am at it and analyze the situation, nope, no fire door open, back drafting badly! I close the dampers, including the intake on the draft fan, now it is still smoking from the feed door (never seals airtight, hotblasts suck like that) and around the stove pipe leading to the tripple wall which goes outside. My first thought is, "okay, must be massive stack effect issue and the exhaust fan is not working." so I leave the basement door open, open more basement windows. The smoke decreases basically to nothing and what is still coming out of the stove pipe is blown out the other windows quickly.

I finally find my multi-meter, the circuit is not drawing crap for the exhaust fan. Should be about an amp or so, nada, zero. I am thinking, "ohhh great, did a diode blow? Cap?" After doing some additional checking I come to the conlusion it is blocked. Getting to the top of my flue requires a bucket truck currently, so my bro inlaw brings one over, he doesn't believe me that it could be blocked. Sure enough, we get up there nice ice block froze around the fan blades causing the fan to stall out.

So yeah, you can get condensation in your flue and you also can clog your exhaust fans if you use them. This springs project (once my Son is born) is to wire up a voltage and current monitor for the circuit, so when we do light up, we can still the exhaust fan is running before ever striking a match. I also plan to add a backup battery supply to the exhaust fan and my hotblast blowers, that way if I lose juice we can still starm warm and safe. Actually my fire works well without the exhaust fan, but there was this one situation where we were burning coal that we got some massive backdrafting issues, it was cheap ass coal (read: free) so to be safer than sorry, I swore I'd always keep the flow going the right way With the little one coming very soon (next week or so) anything that allows us to heat cheap and keeps us safe is a must have!

Sorry kind of a long story, but I am in that mood tonight

Tes

If you bake, be careful. Moe from the Three Stooges once said that "He had a cake fall once and it killed the cat.

 

[RaisedByWolves]

Outside wall. Goes from the stove out through the wall and then straight up about 25'. I was thinking condensation myself but that seemed like an awful lot of water he was describing.

I don't believe there is a flue in his system. Black pipe from stove to wall collar.

With the weird weather we had sat/sun, my money is on condensation.



Everything in my garage was dripping saturday, now its all just rusty.



.

 

[johnha]

Thanks guys, he said his cap screen was so caked he was surprised smoke was getting out. After he cleaned the screen all was well.