Key Damper With Rear Vent Wood Stove

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kvesi122

Member
Nov 20, 2018
41
Worcester County Mass
Hi All,

Pardon the newbie question but is it safe to run a key damper on a rear venting wood stove? Quadrafire Cape Cod with a 1.5' rear vent run leading into a T-cleanout and then 24ft of vertical single wall pipe run through a clay lined exterior chimney.

I'm getting really strong draft on cold nights and shorter burn times than expected with 2 year seasoned red oak.

The stove gets nice and hot but I can't control the secondaries with the air shut. If I close things down on a small coal bed after climbing to 450 it can get up to 750 depending on the temp/wind outside.

Thank you!
 
Do you have a temp guage on the stove pipe? It could be the stove needs to be turned down sooner. Stove temp is not a good guide for this on a cold start. How thick are the splits that are being loaded? How tightly packed are they?
 
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Tightly packed with 4 inch+ spits mixed in with 1-2 6 inch splits. Using an IR gun on the stove pipe just before the T registers a 320-350 degree temp.

If I turn down the stove sooner it slowly creeps up to a strong secondary burn that can't be shut down (45 mins later).
 
You absolutely can run a key damper with a rear vent stove. But with 24' of external clay lined chimney you should not have to at all. I would check all of your gaskets etc for leaks. Something just doesn't add up
 
It is the nature of secondary burn to get hotter as it kicks in. Try starting to close the air in increments when the surface stove pipe temp is around 200-250º.
 
I have a surface meter lying on the stainless tee snout on my rear-vent setup. I also have a key damper but don't use it, with only 17' of chimney.
24ft of vertical single wall pipe
That's rigid stainless chimney, right, not connector pipe?
 
The single wall pipe leading to the T from the back of the stove is rigid. About 1.5-2 ft above the T is where the stainless flex liner was fed down from the top and connected. ~24 ft of 6” vertical flex liner running inside the clay lined chimney (exterior) uninsulated.
 
Tightly packed with 4 inch+ spits mixed in with 1-2 6 inch splits.
Thicker splits will off-gas slower, and slow the burn some.
 
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