Is this the primary air control lever for a 1975 Defiant? How does it work?

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Spano89

New Member
Dec 13, 2023
9
Alabama
[Hearth.com] Is this the primary air control lever for a 1975 Defiant? How does it work?
 
Ha yeah i had that stove 35 years ago. It was a beast. That if i remember correctly is an air control that is auto controlled by heat. The metal chain or some other part lowers that metal flap when the stove gets hot to lower air intake. Of course i could be wrong on that but that's how it worked on mine.
 
Yes. Inside the top part behind the metal cover is a bimetallic coil that raises and lowers the chain based on stove temperature to try and maintain a steady heat output. You set the lever where you want (toward the flue collar = lower) and supposedly it will self regulate from there. Whether or not it actually achieves what's intended is a separate question.
 
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i have one on my defiant 1. that is exactly how it works. once you get it to where you want it, just leave it. when the stove is cold it will be wide open and as it heats up it will close and hold the same temp that you set it at. mine works great. the stove manual says that low is 450 on the cooking plate that is oval on top. high is 700 degrees i run mine at 600 give or take 25 degrees. beware if you run it at 450 degrees it will creosote your chimney really quick and you could have a chimney fire. if you run it with the damper open and the exhaust goes straight to the chimney it very easy to get it hot. i would get a magnetic thermometer so you will know how you are doing. if you run it with the damper closed the little teardrop air control on the left side should be wide open for the secondary fire to work. build your fire up against the baffle on the right side of the stove and you'll have no problem with secondary fire. if you run the damper closed you will notice a dip in the temperature because the smoke now goes thru the hole on the bottom right for secondary burning of smoke. it will dip because of the wood on the top is not burnt because everything is going out the bottom in about 2 to 3 hours the temperature will raise a bit before going down. on my system i get another 1.5 hours out of a full load which means i get 7 to 9 hours out of a full load of wood. things will change for you depending on the species of wood that you are burning and your chimney Hight,
 
i have one on my defiant 1. that is exactly how it works. once you get it to where you want it, just leave it. when the stove is cold it will be wide open and as it heats up it will close and hold the same temp that you set it at. mine works great. the stove manual says that low is 450 on the cooking plate that is oval on top. high is 700 degrees i run mine at 600 give or take 25 degrees. beware if you run it at 450 degrees it will creosote your chimney really quick and you could have a chimney fire. if you run it with the damper open and the exhaust goes straight to the chimney it very easy to get it hot. i would get a magnetic thermometer so you will know how you are doing. if you run it with the damper closed the little teardrop air control on the left side should be wide open for the secondary fire to work. build your fire up against the baffle on the right side of the stove and you'll have no problem with secondary fire. if you run the damper closed you will notice a dip in the temperature because the smoke now goes thru the hole on the bottom right for secondary burning of smoke. it will dip because of the wood on the top is not burnt because everything is going out the bottom in about 2 to 3 hours the temperature will raise a bit before going down. on my system i get another 1.5 hours out of a full load which means i get 7 to 9 hours out of a full load of wood. things will change for you depending on the species of wood that you are burning and your chimney Hight,
What temperature does it maintain at when you close the damper? I've been having trouble with mine keeping the temperature above 500 with the damper closed, but maybe it's because I don't have the air drop all the way open.
 
I don't think it's calibrated, just goes from "high" to "low". With that said your chain could be out of adjustment. When the stove is cold, the flap should just barely hang open when the lever is on the lowest setting. If the flap is closing too early and the fire really isn't getting enough air you can try adjusting the chain up a link.

you should always burn with the damper closed except for a cold start or when reloading. Then once you close the damper, stove temp is controlled by the air lever. I usually start with the air fully open after each reload and gradually turn it down in 10-15 min intervals.
 
also mine does the same thing. when you close the damper the teardrop air on the side should be wide open. also the hot gases instead of hitting the top and it takes it's time getting to the spring to going away from the top and goes across the bottom around the back of the stove and right by the spring so it is more sensitive to how the stove runs. i usually run my stove at 600 give or take 25 degrees on the cookplate and when i flip the damper the temperature drops and i open the air a little more because of the sensitivity and it runs about 525 degrees but pumps out even more heat