Blaze King thermostat not working...help!

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Rangerbait

Feeling the Heat
Dec 17, 2016
456
Shepherdstown, WV
Gents,

My King model stopped working. It appears that the thermostat is not allowing the damper to open, regardless of the position I set the thermostat to. The only way I can keep the fire going is to keep the door cracked, and of course the cat disengaged. This just started happening yesterday, and I have already burned about a cord this season. Yes, my wood is dry (sub-20% Ash for the most part). Suggestions?
 
When you rotate the knob, can you hear the flapper clack against the full open and full closed stops? You must confirm that your knob is actually turning the rod. A small set screw fixes the knob to the rod and may have loosened.

The fail safe position for the stat is closed which is good, but so rare that it’s hardly worth considering.

If you can hear the flapper flapping then I would be looking at my chimney for blockage.

Was this all of the sudden or gradual? Does it feel normal when you turn the knob?
 
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Gents,

My King model stopped working. It appears that the thermostat is not allowing the damper to open, regardless of the position I set the thermostat to. The only way I can keep the fire going is to keep the door cracked, and of course the cat disengaged. This just started happening yesterday, and I have already burned about a cord this season. Yes, my wood is dry (sub-20% Ash for the most part). Suggestions?
Yeah, as @Highbeam mentioned, be sure the rod is turning with the knob. if that is the case is easy fix.
 
A pair of vice grips on the rod will work if the knob is somehow destroyed.

Might even work better than the knob since such a tiny rotation has such a huge effect on output. For now though, let’s just get you operational.
 
Feels normal, and I can hear the flapper doing its thing...I'll have to get up and take a look at the pipe. I checked it about a month and a half ago before I started burning, and it was clean as a whistle after 8 cords last season.
 
Is the knob stopping at 6:00 o'clock pointing to the floor?
 
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Also check the intake behind the stove. If you have an OAK be sure is not restricted.
 
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If your cap has a screen, they can rather suddenly clog. Kind of a death spiral.

Animals, snow, sudden collapse of internal creosote, can block the chimney and ruin draft.

The oak for this stove is an actual sealed intake so if you have an oak, be sure it is not blocked.

Good news on the flapper working. At full hot the knob should hit the stop and be pointing straight at the ground.
 
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heres mine right as I type.
 

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Odd story. He is not complaining about a ton of smoke every time he opens the door, so I wouldn't suspect the chimney cap right away, unless he just didn't mention it.

It works with the door cracked.

This says to me plugged cat (just hit it with a flashlight and soft brush/shopvac), or obstructed air intake. I haven't seen the guts of a king but I imagine that the odds of the intake getting plugged in such a way that the flapper still works - in the middle of burning season - is really really low unless it's on an OAK.

If this is a plugged cat, it will be the first ever plugged cat I have ever heard of on a King.

My money is on the OAK, if there is one.
 
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Odd story. He is not complaining about a ton of smoke every time he opens the door, so I wouldn't suspect the chimney cap right away, unless he just didn't mention it.

It works with the door cracked.

This says to me plugged cat (just hit it with a flashlight and soft brush/shopvac), or obstructed air intake. I haven't seen the guts of a king but I imagine that the odds of the intake getting plugged in such a way that the flapper still works - in the middle of burning season - is really really low unless it's on an OAK.

If this is a plugged cat, it will be the first ever plugged cat I have ever heard of on a King.

My money is on the OAK, if there is one.
Going for what he mentioned on the OP, he did try with bypass open. That why I stopped suspecting a clogged cat. If the knob is moving the rod correctly, I still blaming the intake or oak, if one is installed. Let's see what we hear from him.
 
Going for what he mentioned on the OP, he did try with bypass open. That why I stopped suspecting a clogged cat. If the knob is moving the rod correctly, I still blaming the intake or oak, if one is installed. Let's see what we hear from him.

I don't think you can rule out the cat from his original story. He tried with the bypass open and the door cracked, and it worked. In that case, it could be that the cap is almost plugged and he needs the extra draft to draft at all, or that the cat is plugged and the bypass fixed it, or that the oak is plugged so the only combustion air comes from the open door. All 3 are possible.
 
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So finally got a chance to get up to take a look at the flue...still looks good to me, and the cap/spark arrestor did not have significant creosote buildup.

Blaze King thermostat not working...help!

I can no longer get the cat to glow under any circumstances, and when the fire is raging with the bypass open, I’ll engage cat (cat probe way into active range), and the fire just gets choked out.

Bad Cat?? I’m going to be bummed if this is a yearly consumable at $200+ a season.
 
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From full flames in bypass mode to this, and then the fire dies out after Cat is engaged.

View attachment 234345

Have you tried loading North South? Brushed and vacuumed the face of the cat off?

Lift your flue off the stove with the bypass closed and stick your phone in and take some pictures/videos of the back side of the cat with the flash on.
 
Lift your flue off the stove with the bypass closed and stick your phone in and take some pictures/videos of the back side of the cat with the flash on.

Good idea. Reach in and swing the flap up on the back of the cat for a look. Should swing up easily. At least mine does?
 
Including if you have a dead cat cause you close the bypass the fire should not die. It means the cat is plugged. If with bypass open and door shut/latched the fire is fine but when you close the bypass it dies, the cat is plugged. Period. Do you have ceramic or steel cat?
 
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Whoa. Flue looks great. I agree that a plugged cat seems to be the most likely issue.

There is no swinging flap, just a welded in steel curtain behind the cat. Vacuum the face of the cat with the soft end of the flexible shop vac hose trying to not only clean the face but suck the cells out. I’ve even blown out the cells with low pressure compressed air.

Imagine a honeycomb with each cell packed full of honey. You can verify clear cells by sticking a cell phone camera up in there and taking photos looking right into the cells.
 
There is no swinging flap, just a welded in steel curtain behind the cat

May need some clarification? When I vac. the backside of my cat area I can flip up the "curtain" to ascertain the condition/cleanliness of the backside of the cat area. Soot/pipe buildup can fall down and buildup in this area with use if not cleaned for extended periods. My model may be different. Guessing so? Ill have to look at the parts. Or maybe I am dreaming! Ive been in there many times cleaning.
 
Including if you have a dead cat cause you close the bypass the fire should not die. It means the cat is plugged. If with bypass open and door shut/latched the fire is fine but when you close the bypass it dies, the cat is plugged. Period. Do you have ceramic or steel cat?

Whatever came with the stove...ceramic I guess?
 
Whoa. Flue looks great. I agree that a plugged cat seems to be the most likely issue.

There is no swinging flap, just a welded in steel curtain behind the cat. Vacuum the face of the cat with the soft end of the flexible shop vac hose trying to not only clean the face but suck the cells out. I’ve even blown out the cells with low pressure compressed air.

Imagine a honeycomb with each cell packed full of honey. You can verify clear cells by sticking a cell phone camera up in there and taking photos looking right into the cells.

I have 9 cords through that flue with no sweep yet...the stove ran awesome last season, but has been a dog this season. I did vacuum the face of the cat before I started burning this season, and did get SOME glow early on, but now nothing. Can you take the cat out to clean it?
 
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