Water condensation in the pipe, what can I do?

[Hammerjoe]

I have a Harman Accentra stove that is used only when the outside temps are below -20C.
The main heater of the house is a mini split heat pump system.

So that means that the stove is rarely used in the winter.
The issue I have been battling for years and I dont know how to solve this, is that condensation forms inside the chimney pipe and it ends up pooling at the bottom of the T pipe and when its full it leaks.

The pipe goes out of the stove about 2 feet thru a wall into the basement stairs and with a T shoots up to the roof.

I assume because the air in the basement stairs is cooler than the room where the stove is located it creates alot of moisture inside.

I tried plugging the t section with rags so that no air would move inside the pipe but they just get damp and end soaking anyway.

Has anyone have this situation before or has any ideas how it can be solved?
I am concerned that the pipe will eventually start to rot.

 

[zrock]

Are u sure water is not getting in the top of the pipe?

Sent from my SM-G950W using Tapatalk

 

[Hammerjoe]

Yes Im pretty sure. I thought that was the issue and I replaced the top with three different types. Its impossible for the water to get in from it.
Its condensation, I am guessing because the stove is a warmer place and the pipe is in a cold place a draft is generated and that difference in air generates moisture inside the pipe. Thats why I would like to know if theres anything that could block it.

 

[Mt Bob]

I bet you do not have an OAK?

 

[Hammerjoe]

I bet you do not have an OAK?

OAK? Not sure what it means so Im going to say no!

 

[Mt Bob]

Outside air kit.Basically,you have a connection/flexible tube,plumbed to your stove,so it uses outside air for combustion.Use the search box above,a million threads about it.I suspect,when you turn on an exhaust fan,bathroom or/and kitchen,it is drawing in air,causing your moisture problem,the warm/cold,and tall pipe inside.

 

[Hammerjoe]

Outside air kit.Basically,you have a connection/flexible tube,plumbed to your stove,so it uses outside air for combustion.Use the search box above,a million threads about it.I suspect,when you turn on an exhaust fan,bathroom or/and kitchen,it is drawing in air,causing your moisture problem,the warm/cold,and tall pipe inside.

I suspected that was what you were referring to but I could not think of the acronym for some reason.

Hmmm, That gives me an idea. I opened the back of the stove and looked at the air intake and the little flapper inside was indeed moving slightly showing that there is indeed a draft.
I put a plastic bag to cover it with an elastic band to create a seal temporarily.

The only other place the air could leak in is thru the door. I will check that later.

Is there anything I could use in the flapper thing that would make it stick in the closed position?

 

[Mt Bob]

You are on the right track,but are under the misconception(like lots of people) that pellet stoves are airtight.They are not.The rope gaskets used for doors,ash pans,etc,are not airtight,the stove is dependent on negative air pressure for stove to function,so,they do not need to be air tight.Also,your combustion blower is not air tight.There is a gap,there,but,when it is running,a small amount of outside air is drawn/forced in.Sealing the air intake will probably help,but does not take much of a gap for a big temperature change.