wood stoves

[MotorSeven]

Back puffing is poor draft or marginal draft with cross winds pushing air down the flue from above. Add a stick(24, 36, 0r 48") of flue pipe above the roof. This will increase your draft and is a cheap easy fix. Post up some photo's of your flue set up on the roof and how far away it is from the peak or any other obstruction. What is your total flue length from stove to cap right now?

 

[8N Ren]

It was definitely from the HRV. I turned it off, had all the windows and doors closed, no back puffing. I don't remember off the top of my head what the length is, guessing I'd say 15 ft total top to bottom.