Blaze King thermostat

[CaseyForrest]

So I initially thought I had a defective thermostat.

The Princess didn’t operate the way the King does, I could use all of the range on the thermostat and produce the heat we needed. The King however only seems to have a useable range between about 330 and 6 on the dial. Anything lower than 330, even with a cold stove, positions the flapper completely closed.

Thinking there was something wrong I sent a message off to Blaze King. After not hearing back, and not wanting to have issues at this point in the season, I bought a new thermostat. Well, the new one operates exactly the same way. It does have a little more range say between 3 and 6, but that’s it.

I didn’t install the new thermostat since it wouldn’t have changed anything, and the point between 3 and 12 on the dial has the tab fully disengaged from the spring inside the thermostat. I don’t intend to adjust anything but it certainly seems like it could have a full useable range with finer control over the heat output.

Curious what others range of use on the thermostat is? Having only 1/4 of the range be useful is a small window to operate in and not have the cat go over 1800 on every fire.

 

[moresnow]

Very common. Many BK stoves have a limited sweet spot of therm. knob adjustment. It doesn't mean you have less range of settings. Your range is simply compressed into a smaller zone of knob movement. My Sirocco happy long burn setting is 315 roughly. Of the two Princess models I've installed one burns low at 3 and the other sets low at 1. All different due to venting differences and local atmospheric influence.

 

[Short timer]

So I initially thought I had a defective thermostat.

The Princess didn’t operate the way the King does, I could use all of the range on the thermostat and produce the heat we needed. The King however only seems to have a useable range between about 330 and 6 on the dial. Anything lower than 330, even with a cold stove, positions the flapper completely closed.

Thinking there was something wrong I sent a message off to Blaze King. After not hearing back, and not wanting to have issues at this point in the season, I bought a new thermostat. Well, the new one operates exactly the same way. It does have a little more range say between 3 and 6, but that’s it.

I didn’t install the new thermostat since it wouldn’t have changed anything, and the point between 3 and 12 on the dial has the tab fully disengaged from the spring inside the thermostat. I don’t intend to adjust anything but it certainly seems like it could have a full useable range with finer control over the heat output.

Curious what others range of use on the thermostat is? Having only 1/4 of the range be useful is a small window to operate in and not have the cat go over 1800 on every fire.

@bkvp

https://www.**********/talk/threads/2020-21-blaze-king-performance-thread-everything-bk.181827/stars are h e a r t h. com

 

[CaseyForrest]

Very common. Many BK stoves have a limited sweet spot of therm. knob adjustment. It doesn't mean you have less range of settings. Your range is simply compressed into a smaller zone of knob movement. My Sirocco happy long burn setting is 315 roughly. Of the two Princess models I've installed one burns low at 3 and the other sets low at 1. All different due to venting differences and local atmospheric influence.

Thanks for the insight.

That’s why I purposefully checked both stats cold. This eliminated all outside variables. While I agree the stove will function fine, it seems odd to have the range of operation on the dial be 100% more than the functioning range. If the flapper is 100% closed, cold, with the knob at 3 then this will reduce operating range to between 4 and 6 as the flapper will start to trend closed as the stove heats up.

180 degrees of adjustment from the factory limited to what, 30 degrees of actual, is a pretty small window.

Not complaining, just seems odd.

 

[bkvp]

https://www.**********/talk/threads/2020-21-blaze-king-performance-thread-everything-bk.181827/

Thanks. I monitor all the threads and appreciate the heads up....

 

[Short timer]

Thanks. I monitor all the threads and appreciate the heads up....

You’ve helped me out a ton, never ever witnessed the customer service your company provides.

 

[CaseyForrest]

Thanks. I monitor all the threads and appreciate the heads up....

Is this typical operation of a King thermostat?

 

[Short timer]

I think I confused him putting that link in with the tag to get him here.

 

[bkvp]

Is this typical operation of a King thermostat?

So the operating range of each thermostat is unique. We purchase massive rolls of bimetallic material. Depending upon the model, we cut the raw material to a specific length. Again, depending upon the model, we put a certain number or portions of revolutions into the material. Depending upon the model, we then bake it at a specific temp for a specific time frame to create memory. I suspect that while there are off the shelf springs available, our proprietary process sort of make it unique and hard to replicate.

Is the King a model 1107, which we made until December of 2019 or a new model, the King 40? The springs and therefore operating ranges vary.

 

[bkvp]

I think I confused him putting that link in with the tag to get him here.

I'm easily confused. Ask my wife!

 

[CaseyForrest]

It’s an 1107 manufactured in 2017 if my memory serves. Installed as a new stove a month ago or so.

 

[bkvp]

So keep in mind a very important factor or two. Draft and fuel. Both are extremely variable. I had an 1107 for nearly 20 years. I have a stack at 15' and the effective range of operation (referencing a clock face) was about 2:30-6:00. I have posted many times, on many sites, that when optimal draft and fuel are both entered into the equation, our stoves can sustain combustor activity at lower consumption (burn) rates than tested. This is great because they burn even cleaner! With my 15' stack and 11' of which was outside, my draft was not ideal. Yet my fuel was C/S/S for 3 years and well under 18% m.c. so that made 2:30 possible when cold out.
There are many folks with less than ideal draft that have more like a 3:00-6:00 range of operation due to their particular parameters, conversely there are folks that can also run lower.

Don't worry about flame, glowing cats etc. See if the combustor remains active (550F) and higher. Turn down the stove slowly, allowing the spring to catch up with the firebox temp. Perhaps move it in 1/4" increments. If you get the stove really hot, the spring constricts and pulls the blade tight to a closed position. This will prevent the cat from over firing. Then it takes even longer for the spring to relax because the stove was very hot. In this scenario, going from high to. let's say 3:00, well that will kill the air for some time...and can result in the catalyst going inactive.

Give it a few months and you'll get the particulars all sorted out for your individual installation. Then I'll hire you to take tech calls!!

 

[CaseyForrest]

So am likely not doing an adequate job of describing what I am referring to. But first lets get some specifics out of the way....

Wood is going on CSS for 3 seasons. Oak, Beech and Hickory that registers between 14 and 18% moisture.

Chimney is about 7' of double wall to the CSB, then 20' of Class A to the cap. I get crazy amounts of draft. As long as I have a decent temp differential, I get 0 smoke spillage on a cold stove.

I am not concerned with seeing any flames in the firebox, the cat works fine. But Ill come back around to this later in this post.

I have successfully dialed in thermostat position for my specific install, sq footage, comfortable indoor temps. It will likely need some tweeking as we are still in shoulder season pretty much doing nightly burns which means 1 very small load burned hot and fast to get the stove and stack up to temp and then a load to get settled in for the overnight.

Here is stat position on a cold stove. This is a bit more counter-clockwise than before, earlier this setting was exactly 3. Its no colder in the house now, so perhaps the spring has some break in?

Stat setting on a hot stove after its settled in for an overnighter. Flapper is completely closed.

Cat temp, and as you can see above, turning the stat down wouldn't accomplish anything because the flapper is already closed.

Stove temp at the cat.....

Temp at the side on the top....

At the Stat....

If I am doing something wrong, by all means......

 

[CaseyForrest]

For reference, a new stat for a King. This would represent the stat dial being at 12 on my stove based on placing the collar with the set screw at the same location as the one that's on my stove.

Am I thinking backwards that the tab touching the spring on a cold stat with the dial at 12 would give more control over the stove than what I have now? Could my dial simply not be set correctly?

 

[bkvp]

How loose is the tension? And just for reference, we use a main tube lid with a glass window. We have found removing the lid results some false functioning as heat loss can be increased with lid off.

Please turn thermostat clockwise until it stops. Post picture of black knob and thermostat blade in room temperature stove.

Thanks....

 

[CaseyForrest]

Tension seems tight and notchy compared to the Princess.

I only had the lid off to get a temp reading.

Thanks for taking the time to appease an overthinker.

 

[bkvp]

Both are perfect. Tension should be snug.

Make 100% certain the blade is horizontal before reassembling the lid.

 

[CaseyForrest]

Alright. Thank you.

 

[Short timer]

When I first got my Princess, I could turn my stat down to the lowest setting and it would never stall. I’ve replaced the cat a couple times already and could never match the performance of that first cat. Now I’m in the range you’re operating at.

This sounds like a difference in the cat sensitivity between the two stoves to me. I too thought about it too much, even changed the thermostat like you did. Finally gave up and just run the stove in the range it lets me.

 

[Short timer]

Did you have an issue with the cat stalling at low settings, or did you just pull the cover off out of curiosity?