Defiant Model 1975 CAT Questions, fire coming up pipe, sound post damper

[newhampshaguy]

First, thank you all for your participation and knowledge sharing, I have lurked this site for some time. I am experiencing a new phenomena with my stove and would love your opinion.

This picture was taken this past Saturday . From my limited understanding, the chimney pipe is looking more or less clean, and the collar is not too bad (maybe I am wrong on this ? ). Additionally, is the disparity between the two abnormal?


This video was taken on the same weekend. As my stove gets up to temp, I am seeing quite a bit of flame coming up the connector/collar, more than I ever recall. I apologize for the fan noise in the background, but you can get a sense of the sound and rate at which it is coming up at anyhow. Note that this fire was not stacked very high in the box, when it is, the sound is much more intense, to the point where it sounds almost violent, and causes me to shut the damper sooner than I often would like. Should I be concerned about this?


This last video is right after I shut the damper, there seems to be quite a bit of noise coming from inside the collar, I imagine due to the temp there is some creosote burning off...but is this at a level that would be of concern to you?


At the beginning of the season i mistakenly burned some moist wood, ~25%..but I caught my mistake early and have almost exclusively been burning deadfall hardwood that is all quite dry.
Sincerely appreciate your input.

 

[begreen]

Hard to say but that might just be metal expansion noise.

 

[Diabel]

Two things.

Do you have a pipe thermometer and a cat thermometer? Every fire you build will act different. Some will take off fast others will be slow to take off. With griddle temp shown in your vid I would be closing the damper for sure.

With open damper these stoves will pull flames into the flue for sure. Mine will if I let it. I believe you can eliminate that tiny gap by wiggling your pipe some and seating it some more on the flue collar. I have seen pictures of some 1/2” gaps between the collar and the male end of the flue pipe. These can be fixed by stuffing a rope gasket in between. That is not the case with yours, looks like you have a pretty good fit.

 

[newhampshaguy]

Two things.

Do you have a pipe thermometer and a cat thermometer? Every fire you build will act different. Some will take off fast others will be slow to take off. With griddle temp shown in your vid I would be closing the damper for sure.

With open damper these stoves will pull flames into the flue for sure. Mine will if I let it. I believe you can eliminate that tiny gap by wiggling your pipe some and seating it some more on the flue collar. I have seen pictures of some 1/2” gaps between the collar and the male end of the flue pipe. These can be fixed by stuffing a rope gasket in between. That is not the case with yours, looks like you have a pretty good fit.

I have neither thermometer you have mentioned. I will grab a pipe thermo asap, unfamiliar with the cat thermometer, so I will have to look into that. What pipe temps do you typically see?

Appreciate your input re: the flames into the flue!

 

[Diabel]

Is the pipe single wall or double?

 

[newhampshaguy]

Is the pipe single wall or double?

double wall

 

[Diabel]

In that case you need a probe type of thermometer in order to get a correct reading. It should be placed ~ 18” above the stove. For cat stoves the optimal temp reading should be between 350 and 500 degrees while the stove is cruising.

 

[newhampshaguy]

In that case you need a probe type of thermometer in order to get a correct reading. It should be placed ~ 18” above the stove. For cat stoves the optimal temp reading should be between 350 and 500 degrees while the stove is cruising.

thank you for this info