Knob creaks and turns hard

[reaperman1]

Does this mean the flapper isn’t working properly if the knob creeks and turns hard? Since day 1 of owning this stove, it has never operated as other BK owners swear by. I’m constantly moving the knob to adjust the output, mainly shutting it down to keep it from getting too hot. A while after reloading the stove, I’ll turn the knob down to keep the flu temps in range. An hour after the burn seems to settle, the cat temps will climb, the cat will glow and get over 1300 degrees (measured with a Auber probe). And the flapper will not have moved from where I initially set it. In fact it’s always where I set it. Except on a rare occasion or two when I have the flapper almost closed i notice it’s closed by itself but doesn’t open because it’s chocking the fire out. On my stove, I can visually see the flapper, and that’s how I adjust its stopping point. Not by where the dial shows. I currently have 3 wood stoves, and have had 2 more in past homes. This stove requires way more attention than any stove I’ve ever used.

 

[stoveliker]

Something sounds wrong for sure.

Beyond that, something needs lubrication.

And why can you see the flapper?
Having the cover off should not be normal operation mode imo.

 

[reaperman1]

The first photo is a pic of the front of the stove, the center is the thermostat. Looking thru the gap on the left side, center, gives full view of the flapper. (The 3rd picture). The flapper itself is wide open without any cover. It’s been that way since new, I assume it’s factory. The only covered part is a box on right hand side of the flapper itself. Which is the very center of the stove.

Looking at the stove head on, the 4” metal strip that goes to the width of the stove is welded in place. Which is rather annoying because the duel blower fans in the rear, draw air thru the slits on the top and bottom of the 4” strip. There is a blower fan on each side of the center unit. By drawing in air they can also draw in debris, which they do. This debris can fall directly on the exposed flapper mechanism since it’s not covered. To me this could cause the flapper not to move as freely as it should. Not only that, there is a metal plate the size of the stove that separates the bottom of the stove and the top of the wood storage. All of the debris the fans draw in collects on this bottom plate without access to clean it off. It would have been much simpler to have made a way for the 4” strip that goes the width of the stove removable. It would have given access to the flapper unit and a way to clean all of the debris that gathers under this area. It would also help keep debris from getting into the blower fans.

 

[stoveliker]

Hm, I can see what you mean.

I don't know the mechanism of the boxer well,.and I don't know anyone here that has one too.

@BKVP the thermostat seems to not do its thing here?

 

[reaperman1]

Here is an audio file as I rotate the knob back and forth.

 

[Duds13]

Mine on my Ashford 30.2 kinda sounds like that from the 6:00 position for the first couple small dial downs then gets quiet. My flapper works though

 

[stoveliker]

That's from a bug-horror film

Mine occasionally sounds a bit like that, though less severe.
I think some graphite at the right places will help with that.

The coil+flapper assemby not doing what it is supposed to do is not right tho.

 

[Duds13]

We should probably drink some Knob Creek while discussing the knob creeking?

 

[BKVP]

Who installed the stove? The lower valance is not welded to the stove. There are two fasteners holding it in place.

When was it installed?

BKVP

 

[reaperman1]

Who installed the stove? The lower valance is not welded to the stove. There are two fasteners holding it in place.

When was it installed?

BKVP

I had a HVAC installer put the chimney thru my roof and install the support box. I placed the stove and hooked up the double wall pipe. Im going into my 3rd season of burning it. It was purchased in Duluth Mn, as a floor model. Everyone said there is a learning curve to using a cat stove. I figured out how to use it the way it is. But its just totally different than everyone else describes. The flapper never moves unless I have it within 1/16" or less of fully closed. And that has only happened a few times over the years. I can tell when it does happen because it will not re-open and I'll have a half load of wood in the firebox thats being snuffed out. The flapper on my stove does not have a hole on one side of it like some BKs do. So when its closed, it gets very little air if any.

In not quite sure what you are calling the valance. If its the 4" tall piece that goes the width of the stove and covers the thermostat. That piece has 4 spot welds, two in each corner welded to the top ash lip, thats on the bottom of the stove door. You can see in the photos below I circled the spot welds. Looking at the photos you can see little slot by the red circles. Thats where the hook sits that opens the bypass door. So the ash lip and the 4" piece that covers the thermostat (valance?) are welded together.

 

[reaperman1]

Who installed the stove? The lower valance is not welded to the stove. There are two fasteners holding it in place.

When was it installed?

BKVP

My apologies, I found the two fasteners. They are not very visible with the door closed.

 

[BKVP]

My apologies, I found the two fasteners. They are not very visible with the door closed.

Now that you can get the lower valance off the unit, you should be able to access the the thermostat.

DO NOT loosen the set screw closest to the thermostat body. See if you can get some lubricant onto the the thermostat assembly.

Before you lubricate, vacuum any dust or debris away from the thermostat body. Make certain, by using a long screwdriver and pressing down on the thermostat blade, that it is not hanging up on anything. You need to make certain no wires or zip ties are running over the thermostat that could cause issues.

Post back what you find. DO NOT remove the thermostat if you can avoid it. If you do, it will take the stove out of service until a new thermostat is ordered and shipped.

Do not expect to see the blade moving...it moves very slowly. You should see it move when you move the black thermostat knob.

BKVP

 

[reaperman1]

I was able to get the squeak to stop by taking a Q-tip and rub some automatic transmission fluid on the long rod end near the thermostat box. I also put some on the flapper roller. The whole mechanism rolls alot more freely and quiet. Also there is nothing impeding the flapper from moving freely. I cleaned everything up and and vacuumed everything I could reach. I assume the two washers in the center of the flapper are there for spacers to keep the flapper from rubbing the sides of the housing. They both move freely as I would expect them to.

 

[BKVP]

Great...I'd suggest some high temp antiseize next time. Antiseize will collect debris.

When you turn knob to high, with a hot fire, does the blade close or start to close?

BKVP

 

[reaperman1]

The cat temp is the left Auber gauge and the right one is the flue temp. The fire was reloaded approx 1.5 hrs ago, so it’s well established. I turned the dial to high for a few minutes. Then I marked the thermostat box, even with the top of the flapper when I opened it up all of the way. I took the photo about 4 minutes later and the flapper hadn’t moved. You will see my mark above the screw on the thermostat

 

[BKVP]

4 minutes isn't much of a test. Let it run for a bit longer. The thermostat blade doesn't move at a perceptible rate, rather over time.

BKVP

 

[reaperman1]

After 35 minutes of running the stove wide open, the flapper never moved. The cat was almost 1000 degrees and stack almost 700. I was wondering if I used a trigger torch on low flame and heated the thermostat on body, if that would move the flapper? I've watched videos of BK demo's using a hair dryer to illustrate how the unit works. The demo's show the flapper moving pretty quickly.

 

[Dieselhead]

After running wide open I’d expect the cat to reach much higher than 1000 degrees. What’s your wood situation?

 

[BKVP]

Are you comfortable removing the thermostat to test it? It has to be removed to test it.

BKVP

 

[all night moe]

After running wide open I’d expect the cat to reach much higher than 1000 degrees. What’s your wood situation?

This is a good point Reaper.
CAT stoves are very finicky with moisture. Are any of your other stoves with CATS?

 

[reaperman1]

After running wide open I’d expect the cat to reach much higher than 1000 degrees. What’s your wood situation?

I understand the wood moisture. Trust me most of my wood is at least 7 years minimum and older split and dried red oak and ash. My issue isn’t with the stove/cat getting hot it’s the stove/cat getting too hot. On a typical reload, I burn until it’s good and hot, the stack temps are easily in the 700’s and climbing. At that point I turn it down for a while and the stack temps fall into the low 600’s. From there I try and keep a few rolling flames, most of the time the flames are 80% blue. By this time the flapper is only open about a little more than 1/8”. Within an hour, the flames will disappear and the stove will start to ping and the cat has risen to 1300+ and climbing, along with my stack temps. So I need to close the flapper all of the way and the cat and stack temps plummet. Then I need to re-establish the fire by opening the flapper to get flames again. With flames present it takes away some of the duties of the cat. So the cat will operate more around 1000 degrees.

This morning when I did the test before work, the stove was hot, which BKVP wanted. It wasn’t a raging fire, but it was a deep bed of coals and whatever left of the splits from a previous load only 3 hrs earlier. The test I did the other night I cut off before my stove got to the point it where it starts getting too hot.

It odd, the more I turn the stove down within the first two hrs, the hotter it gets.

 

[reaperman1]

Are you comfortable removing the thermostat to test it? It has to be removed to test it.

BKVP

I’m comfortable, I may wait a bit for a little warmup so I can re-caulk. Whatever the results are, I’m perfectly fine either way. I just don’t trust packing my stove full like BK users do. Because with the flapper almost shut, I should be on low and slow mode. But after a while the flames disappear and the cat goes crazy. The last thing I need is a full load of wood with climbing cat and stack temps and me at work. Thats where I figured the thermostat should sense this and shut the stove down, but it never does. Again, the only time the flapper shuts itself off is when it’s only open a slight bit, and that’s rare. Then it never re-opens and I’m left with a partial load on black chunks of wood and very little heat output, if any.

 

[stoveliker]

I think your observations ("flames disappear and the cat goes crazy") are perfectly normal. When you close the air, you make more half-burnt gases (smoke etc.) Those are what the cat consumes and what makes heat in the cat.
So closing the air leading to increased cat temps is *what is expected*. I see that all the time.

You don't need flames to burn clean in a BK.
And when you don't have flames, the firebox itself won't produce as much heat, instead it's the (much smaller) cat that produces the heat. This is normal.

" cat has risen to 1300+ and climbing. So I need to close the flapper all of the way and the cat and stack temps plummet. "
I think when the cat temps rise you don't need to close the flapper all the way.
Just let it go. IF (...) the thermostat works, it'll go for a bit and then equilibrate.

"So I need to close the flapper all of the way and the cat and stack temps plummet. Then I need to re-establish the fire by opening the flapper to get flames again."

I don't know why you would need to re-establish the fire. You don't need flames.

THe way to operate the stove is (with a working thermostat) to simply set the thermostat at a setting that makes you comfortable - and leave it there. It'll cycle a bit in temps, but then it'll settle in a rather constant heat output.


I do not know what to think of the flapper observations.
I do know that changing the thermostat by 1 mm (1/25 of an inch) can have huge changes in heat output. I.e. closing it, and the flapper not opening again, may mean you just reached the bottom end of the useful range of operation on the thermostat.
But, I can't say that something is not broken from here.

 

[reaperman1]

I think your observations ("flames disappear and the cat goes crazy") are perfectly normal. When you close the air, you make more half-burnt gases (smoke etc.) Those are what the cat consumes and what makes heat in the cat.
So closing the air leading to increased cat temps is *what is expected*. I see that all the time.

You don't need flames to burn clean in a BK.
And when you don't have flames, the firebox itself won't produce as much heat, instead it's the (much smaller) cat that produces the heat. This is normal.

" cat has risen to 1300+ and climbing. So I need to close the flapper all of the way and the cat and stack temps plummet. "
I think when the cat temps rise you don't need to close the flapper all the way.
Just let it go. IF (...) the thermostat works, it'll go for a bit and then equilibrate.

"So I need to close the flapper all of the way and the cat and stack temps plummet. Then I need to re-establish the fire by opening the flapper to get flames again."

I don't know why you would need to re-establish the fire. You don't need flames.

THe way to operate the stove is (with a working thermostat) to simply set the thermostat at a setting that makes you comfortable - and leave it there. It'll cycle a bit in temps, but then it'll settle in a rather constant heat output.


I do not know what to think of the flapper observations.
I do know that changing the thermostat by 1 mm (1/25 of an inch) can have huge changes in heat output. I.e. closing it, and the flapper not opening again, may mean you just reached the bottom end of the useful range of operation on the thermostat.
But, I can't say that something is not broken from here.

I do appreciate the feedback. What I’ve noticed in
reading other posts are people run their stoves wide open on a reload for a half hr or so. Then the stack temp hover at around 400 degrees or so. I think, how are they so low? My stack temps are always in the 600’s or more, 400 would be a fire that’s just about out. A good fire produces smoke that goes thru a 1000 degree cat, and exits the stove only 8” later and goes straight up the flu and hits a probe thermometer 18” up and someone’s exhaust temps are only 400? Am I missing something? I just don’t like the flue crawling into the 800’s for too long. I have my alarm set at 900 on my probe. I know my ICC pipe can take the heat but I want you to be safe too. I don’t think I have an overdraft issue. I’m at the bare minimum of 15 feet total chimney, 5’ double wall, and 10’ class A. I never have smoke when I open the stove other than the normal little bit at times that you would expect. Another thing is when the cat and stack temps crawl up, the wood is being consumed more rapidly as expected. The entire load of splits will be coaled up and breaking apart. With a very minimum
air setting on the thermostat. In fact I cant turn the dial down much more without snuffing the fire. So how am i suppose to get 10 hour or more burn times when the lowest setting is burning wood faster?
Keep in mind, the dial position to me means nothing. I can physically see the flapper at all times. So that’s my way of regulating the stove. And thinking it’s not functioning because it’s almost always in the same position regardless of how big or small the fire is.

 

[stoveliker]

I do appreciate the feedback. What I’ve noticed in
reading other posts are people run their stoves wide open on a reload for a half hr or so. Then the stack temp hover at around 400 degrees or so. I think, how are they so low? My stack temps are always in the 600’s or more, 400 would be a fire that’s just about out. A good fire produces smoke that goes thru a 1000 degree cat, and exits the stove only 8” later and goes straight up the flu and hits a probe thermometer 18” up and someone’s exhaust temps are only 400? Am I missing something? I just don’t like the flue crawling into the 800’s for too long. I have my alarm set at 900 on my probe. I know my ICC pipe can take the heat but I want you to be safe too. I don’t think I have an overdraft issue. I’m at the bare minimum of 15 feet total chimney, 5’ double wall, and 10’ class A. I never have smoke when I open the stove other than the normal little bit at times that you would expect. Another thing is when the cat and stack temps crawl up, the wood is being consumed more rapidly as expected. The entire load of splits will be coaled up and breaking apart. With a very minimum
air setting on the thermostat. In fact I cant turn the dial down much more without snuffing the fire. So how am i suppose to get 10 hour or more burn times when the lowest setting is burning wood faster?
Keep in mind, the dial position to me means nothing. I can physically see the flapper at all times. So that’s my way of regulating the stove. And thinking it’s not functioning because it’s almost always in the same position regardless of how big or small the fire is.

I don't think the 400 F flue temps are during charring the load. It'll be higher.

"In fact I cant turn the dial down much more without snuffing the fire . So how am i suppose to get 10 hour.."

By snuffing the fire .. it's fine (it is th goal, generally) to snuff the fire.

You're not burning faster when the cat temps go up. You're burning slower.
95% of the time I don't have any flame.