Issue with smoke coming from the top (I think) of my new VC Dauntless.

[GP in the UP]

Recently had a new Vermont Castings Dauntless professionally installed. It replaced a 1970s Vermont Castings Defiant (which I never had this problem with). Anyway, once the stove gets up and running I engage the cat. At a certain point I will then adjust the air intake to a lower setting for a longer burn. However, I'm pretty sure smoke is coming from the stove once the air flow is reduced. It isn't visible, but I seem to get whiffs of it from the top loader door. After a while it can becoming overpowering. I think it's coming from the top door because when you open the top door with the cat engaged smoke comes billowing out.

The stove is vented from the top (about 4 ft of pipe), with one 90 degree elbow that then runs into the side our 25 foot cinder block chimney. Any suggestions on making the top load door more air tight? Or is there something else I can do?

 

[begreen]

It sounds like this could be a combination of factors. The chimney liner may be better sized to the larger Defiant, the chimney takes longer to warm up due to the lack of an insulated liner and the 90º turn is spoiling draft. All this becomes more apparent as the flue gases cool down when running with the cat. A remedy would be to install an insulated liner and change over the 90 to a pair of 45s in offset configuration.

 

[dvukin]

Recently had a new Vermont Castings Dauntless professionally installed. It replaced a 1970s Vermont Castings Defiant (which I never had this problem with). Anyway, once the stove gets up and running I engage the cat. At a certain point I will then adjust the air intake to a lower setting for a longer burn. However, I'm pretty sure smoke is coming from the stove once the air flow is reduced. It isn't visible, but I seem to get whiffs of it from the top loader door. After a while it can becoming overpowering. I think it's coming from the top door because when you open the top door with the cat engaged smoke comes billowing out.

The stove is vented from the top (about 4 ft of pipe), with one 90 degree elbow that then runs into the side our 25 foot cinder block chimney. Any suggestions on making the top load door more air tight? Or is there something else I can do?

Disengage the cat before opening the top door.