Stuck Thermostat on Blaze King King

[aansorge]

In two years of burning it this has only happened twice to me, but now it has happened to my wife. I load up the King with fuel with the by-pass open and air wide open. The wood catches fire and heats up the stove for awhile. I close the bypass, let the temp probe swing up to just over half-way and turn down the air.

Well 3 times now when the air gets turned down, nothing happens. It just keeps on burning at wide open throttle. A good tap on the air-control knob and a little wiggling and the thing goes back to normal and will shut the air down.

I hadn't told my wife this as it had only happened twice (really, I was planning on telling her!) and came home to a roaring fire today and a stressed out wife (we also had a birthday party going on with 12- 8 year olds).

The stove seems fine...it wasn't glowing or anything. The house was 81! Does running on essentially 3 hurt a Blaze King?

2nd question- has this happened to anyone else?

3rd question- will the tap and jiggle stop working at some point?

 

[jeff_t]

I doubt anything got too hot.

You can pull the top cover off the thermostat housing and try to figure out what's going on. I can't imagine it's anything in the thermostat assembly itself. Maybe the flapper catching on something?

I'd take that cover off and try to replicate the situation. Two screws and some sticky sealant, like RTV, hold it on.

 

[rdust]

Happens to mine if I burn it on max air(3 1/2) for a while. My stove is a 2006 build and doesn't have the screw in the t-stat housing cover to stop it from going to full open like the newer stoves. When it gets hot the t-stat flapper expands and gets hung up under the cover. It's simple to prevent now that I know it does it. The first time I turn the air down I turn it down to the 12 o'clock position and make sure I hear the t-stat flapper bang close(wife does the same thing) before changing the air setting. If I hear the flapper close I know it's not stuck, if it is stuck moving the knob quickly from low to high a time or two fixes the issue.

This doesn't seem to happen if I burn the stove on 3 when I'm warming it up, it only seems to happen if I have the t-stat cranked to the highest position.

It doesn't take long to figure it out, a BK full of flames on a lower air setting doesn't happen so if you have it turned down and see heavy flames you know something ain't right.

 

[begreen]

Can the flapper edges be gently filed down to prevent this?

 

[jeff_t]

I pulled the cover off my stove and snapped a couple pics. The collar on the shaft has an extra long set screw that acts as a stop.



This is what mine looks like with the knob pointing at the last dot (3.5?). Keep in mind this is a sorta hot stove, about 450° over the cat. It will open more when the stove is cold.



Pay no mind to the dust. You're not supposed to take the cover off anyway

 

[aansorge]

Thanks folks!

 

[rdust]

I pulled the cover off my stove and snapped a couple pics. The collar on the shaft has an extra long set screw that acts as a stop. My guess is this isn't set correctly and allows the flapper to open too far and contact the cover.

View attachment 145273

This is what mine looks like with the knob pointing at the last dot (3.5?). Keep in mind this is a sorta hot stove, about 450° over the cat. It will open more when the stove is cold.

View attachment 145274

I would see where the stop is set, and adjust it if it isn't right.

Pay no mind to the dust. You're not supposed to take the cover off anyway

You have an older stove like mine, we don't have the set screw in the top cover. IIRC the newer King and Princess stoves have a long screw in the top cover that prevents the flapper from opening too much. I believe Todd had this on his Princess and Hotcoals may have mentioned it too.

Edit: Found Todd's thread on modding the cover which BKVP advised against. https://www.hearth.com/talk/threads/blaze-king-princess-t-stat-cover-mod.110024/

 

[rdust]

aansorge, does your cover have 2 or 3 screws in it?

 

[BKVP]

I pulled the cover off my stove and snapped a couple pics. The collar on the shaft has an extra long set screw that acts as a stop. My guess is this isn't set correctly and allows the flapper to open too far and contact the cover.

View attachment 145273

This is what mine looks like with the knob pointing at the last dot (3.5?). Keep in mind this is a sorta hot stove, about 450° over the cat. It will open more when the stove is cold.

View attachment 145274

I would see where the stop is set, and adjust it if it isn't right.

Pay no mind to the dust. You're not supposed to take the cover off anyway

Do not loosen or move the allen collar set screw or the thermostat will need to be calibrated in the factory. Jeff, is your stove connected to fresh air? If so, perhaps that is whee all the build up has come from. I would definitely clean it off and put some anti seize on the horizontal shafts.

If you or aansorge would like a replacement main tube lid with the third screw, we'd be happy to send one along.

 

[aansorge]

aansorge, does your cover have 2 or 3 screws in it?

Just 2.

I bought the stove used so I don't deserve any freebees BKVP. Thanks though.

So if I simply don't open the air all the way on reload it won't stick, correct. Alternatively if it does stick just turn it off on off on a few times and it should close the flapper.

 

[jeff_t]

Do not loosen or move the allen collar set screw or the thermostat will need to be calibrated in the factory. Jeff, is your stove connected to fresh air? If so, perhaps that is whee all the build up has come from. I would definitely clean it off and put some anti seize on the horizontal shafts.

Ah, didn't know it was that serious. Post edited

That's three years worth of room air, accentuated by a couple of big, hairy dogs

If you or aansorge would like a replacement main tube lid with the third screw, we'd be happy to send one along.

Mine doesn't open far enough to make contact, even when stone cold. I might take you up on the offer, though, as I hope to not be living there much longer. Might be a good idea for the new owners.