Smokey basement from upstairs stove?

[Nvernon91]

Recently got a new insert and new insulated liner installed. Everything working great but I went down in the basement the other day and noticed it reeked of smoke but nowhere else in the house does. The new insert is on the upstairs and has its own independent flue and the downstairs has a unused old wood stove that runs in the same chimney but different flue. There is loose joints in the old unused basement wood stove pipe. Is it possible the new insert is working properly but downdrafting to the basement from the top of the chimney? The new insert has a bypass dampener and I haven’t noticed any smoke at all coming out from reloading and cold air returns I don’t think are the issue because of locations and lack of smoke from reloading. I checked out the chimney cap to see where smoke was flowing and it really is only smoking 1/3 of the time, no smoke 2/3 time. Of the time the smoke was coming out the top it appeared to be dissipating in the wind. Any ideas if the flue to flue downdraft is plausible as the cause?

 

[DAKSY]

Your insert needs combustion air & it's gonna draw that air from inside you home.
That air needs to be replaced & that replacement air is coming into the basement
through the unused chimney. You'll hafta block that air flow to eliminate the smell...

 

[begreen]

Do the two flues terminate at the same height and close to each other? If so, the basement flue is siphoning the main floor stove's smoke. The remedy is to extend the main floor stove's flue 12-18" or cap off the basement thimble.

 

[EbS-P]

Do you ever use the downstairs stove? If not I would just seal the flue with a chimney balloon. Or seal it at the top what ever is easier.

 

[Nvernon91]

Yes they are a foot apart at the top of the chimney and both the same height minus the new one having a cap that probably makes it a hair higher but not air tight either. Ok I appreciate your guys help, I’m going to seal off the basement flue entrance as it seems a little easier than changing the height at this stage

 

[EbS-P]

Yes they are a foot apart at the top of the chimney and both the same height minus the new one having a cap that probably makes it a hair higher but not air tight either. Ok I appreciate your guys help, I’m going to seal off the basement flue entrance as it seems a little easier than changing the height at this stage

Hang a tag In the The stove saying it’s sealed up. It may save a Smokey mess for someone in the future

 

[Nvernon91]

Just a follow up, I sealed up the air flow issue in the stove pipe in the basement and the problem went away….I appreciate your guys knowledge on this as it was definitely a downdraft to a different flue issue

 

[RIdgefireCT]

Do the two flues terminate at the same height and close to each other? If so, the basement flue is siphoning the main floor stove's smoke. The remedy is to extend the main floor stove's flue 12-18" or cap off the basement thimble.

Hello I have a similar problem one chimney with 3 separate flues servicing 3 separate chimneys 1. Basement, 2. Main floor and 3. Master bedroom. I had the main floor chimney scoped and of course the flue tiles were compromised so I had it lined and had an insert installed. Seemed to solve the smoke in the basement issue until tonight. The other 2 flues have caps on the top - dampers and we keep them closed so not quite sure how basement started to smell? We do have a dryer on the main floor - not the basement and it was running this evening so not sure if that had anything to do with it. Nevertheless I can’t understand if the other 2 flues are closed with top cap dampers and a liner in the useable fireplace smoke could still get pulled into the basement. ? Adding a pic - as you will see I also had the crown re done as well beautifuly !