Blaze King Air Control Question

[scum]

I'm just starting season 2 on my Blaze King Ultra. First season I had a few struggles getting used to the nature of running with a cat - see forum link. Once I worked it out, it runs good but not great. By this, I mean it's not performing as well as I expected.

I can run it hot under full-throttle, but it's not as hot as my previous quadrafire and chews through the wood just as much. I can run it low to get longer burn times but then the heat output isn't really much and the run times are not that exceptional (~8hr) - again not much better than my quadrafire. The details are in the other thread, but I have a very long 8" flue (~25') and am burning lodgepole pine at 15-20% moisture.

I'm starting to wonder about my air control and am hoping someone can tell me if it's normal or worth exploring.

If I rotate the dial high to low, the air flapper 'clicks' closed at the 3'oclock position. This is regardless of hot or cold stove. So this means, I only have from 3'oclock to 6'oclock to work with for air control (what's the point of the other 75% of the dial?). At 3'oclock, my stove usually doesn't have enough to keep the cat from stalling out. I normally have to run the stove at ~4-4:30 to keep an active cat that produces enough heat to be viable and get through most of the night. At 6:00, it's active flame and high heat, but as I mentioned I kind of expected higher heat.

Also, my understanding with the air control is that it would adjust to keep the stove at the temperature you set. This doesn't seem to happen. I set it at ~4:30 and it initially produces good heat with a full load. As the load burns, the stove gets progressively colder. Not drastically... it slowly cools through the night though to borderline stalled out in the morning.

 

[black smoke signals]

I'm just starting season 2 on my Blaze King Ultra. First season I had a few struggles getting used to the nature of running with a cat - see forum link. Once I worked it out, it runs good but not great. By this, I mean it's not performing as well as I expected.

I can run it hot under full-throttle, but it's not as hot as my previous quadrafire and chews through the wood just as much. I can run it low to get longer burn times but then the heat output isn't really much and the run times are not that exceptional (~8hr) - again not much better than my quadrafire. The details are in the other thread, but I have a very long 8" flue (~25') and am burning lodgepole pine at 15-20% moisture.

I'm starting to wonder about my air control and am hoping someone can tell me if it's normal or worth exploring.

If I rotate the dial high to low, the air flapper 'clicks' closed at the 3'oclock position. This is regardless of hot or cold stove. So this means, I only have from 3'oclock to 6'oclock to work with for air control (what's the point of the other 75% of the dial?). At 3'oclock, my stove usually doesn't have enough to keep the cat from stalling out. I normally have to run the stove at ~4-4:30 to keep an active cat that produces enough heat to be viable and get through most of the night. At 6:00, it's active flame and high heat, but as I mentioned I kind of expected higher heat.

Also, my understanding with the air control is that it would adjust to keep the stove at the temperature you set. This doesn't seem to happen. I set it at ~4:30 and it initially produces good heat with a full load. As the load burns, the stove gets progressively colder. Not drastically... it slowly cools through the night though to borderline stalled out in the morning.

Good reading here https://www.hearth.com/talk/threads/blaze-king-thermostat-faulty.48603/

 

[webby3650]

What you are describing does not describe a Blaze King loaded with pine and a tall flue. Short burn times, maybe. Stalled stove unless it's ran at the 4:00 position, no. That's not typical with dry wood and a tall flue. Something's not right here

 

[scum]

I just read through the forum Black Smoke Signals linked. I bought my stove a year ago so I would expect Blaze King would have addressed that issue by now but it does seem like it might fit the bill - or at least is related. I haven't had run-away conditions though so I'm not sure if it's the same exact problem? I'm going to try to check the tstat as suggested in the thread tonight.

 

[jetsam]

I have a BK with a much smaller firebox, and it can go at least 16 hours on pine if I'm burning low. (I could also go through that load in 4 hours, but I'd have to open some windows.)

If I was getting 8 hour burns and low temperatures I would be checking to see if my cat was installed and gasketed correctly, and if my bypass door and gasket were OK. If your cat is missing /dead/permanently bypassed, then your symptoms sound pretty normal. It could also be partially plugged with ash...

Lack of a block off plate could also be contributing somewhat to the issue, but what you are describing is too severe to be caused by lack of a block off plate.

I suggest you figure out a good viewing angle where you can see the cat, put some fresh wood on the fire, turn up the air, turn off the fan, engage the cat, and make sure it glows. (It doesn't have to always be glowing to be working, but with fresh wood and lots of air and no fan, it should glow.)

If you can't get it to glow, then one of the things I said above (dead cat, missing cat, bypass gasket, bypass door) may be the issue. If it just glows in a small area, it could be partially plugged, which is easy to fix with a shop vac.

 

[scum]

Thermostat seems OK testing the way described in the other thread. It does adjust some. At stone cold, it clinks at ~2:00 (missed that before). Once it starts to get warm it goes to 3:00 and stays there. It doesn't really move from there regardless of high or low heat but I expect any adjustments it makes would be slight.

I packed it to the gills last night and tried just leaving it at ~3:00 just to see how it did. It's been a while since I've ran it this low since it's really not enough heat. This morning, still 1/4 full of wood and stove was barely in the active zone - running much cooler than when I went to bed. Thermostat still 'clinks' closed at about 3:00. So again, it seems to just slowly cool off over time. I cranked it back up to get some heat for the family but I'd guess if left alone it would eventually stall out or at the very least just continue to ride at the point of barely active. I do have to eat my words though, at this pace the stove would have gone much longer than 8 hrs on low-low.

I can and do often get the glowing cat. So I'm sure it's fine. Though it could be slightly plugged or the gasket may be out of wack. I have a 14'+ stack on top of the stove so I've been very reluctant to try to pull the pipe off to look down at the top of the cat. I suppose I should just get over it and try to pull it off to inspect it. I have done the dollar bill test on the bypass from inside and it's fine.

I do have a newer home that's fairly tight. Would this be typical symptoms of air starved stove needing a CAK?

My concern is it just doesn't seem to run quite as expected. I expect the tstat to hold a temperature setting through the night and I expected to have a little more on the top end for heat output. When I fired up my load last night, getting the initial hot burn going I tried to get it as hot as possible. I have a thermometer on the center of the top right below the cat probe. Max I could get was ~600. That was regardless of full throttle/bypass closed or partial throttle/bypass closed to push more smoke through the cat.

I'm used to my old quadrafire that could get hot enough to be a little scary especially when burning pine. Am I just expecting more than the stove is designed for and should quite worrying about it?

 

[Stump shot]

How many pounds of wood are you putting in it at reload time? I put about 40 lbs in my Ashford and am good for 24 hours this time of year.

 

[studdriver_40]

Scum.... im new to the site.... scum can you email as soon as you get this. i am having the exact same problem! maybe we can figure something out here. get us both burning were we should be thanks.

[email protected]

 

[begreen]

My understanding is that the thermostat will self-protect the stove from overheating.

 

[studdriver_40]

Talking about turning it down. Can't go any lower than 2.5 without cat stalling out. I'm having same problem as scum

 

[begreen]

Talking about turning it down. Can't go any lower than 2.5 without cat stalling out. I'm having same problem as scum

Might be weak draft. What are the outdoor temps? Describe the flue system from stove to chimney cap including all turns and flue size(s).

Is this a basement install?

 

[studdriver_40]

Yes it's a basement install... I have fresh air kit hooked up to it c if it would make it any better it didn't I don't think. Pipe comes off stove goes to 90 thru wall then another 90 up side of house not quite for sure how high it is. Thinking probably 20 feet high from the exit to wall going up

 

[studdriver_40]

Temps in 30s

 

[scum]

@studdriver_40, I saw your PM. I have just learned never to turn it down that low. Normally, I need the crazy high heat so that works OK. If I turn it to 3 o'clock position it puts out enough heat for shoulder season temps. If I go below 3 o'clock, or go to 3' too soon, it just stalls. In fact, I did that the other night and woke up cold w/ a stalled stove - my fault since I turned it down too soon (aka lazy).

Before the season started, I did a thorough cleaning and pulled the pipe off. Sure enough the bypass was loose and wouldn't hold the dollar bill. I tightened this up (maybe a bit too much as it takes a bit of effort to click it closed now) but it's a good seal now (still owe my son a buck since I tore his). I'm hopeful that this season will see better performance now.

To be very clear, I ask a lot out of this stove - more than I have a right to. This is a ~4500 sqft home. Stove is on main level next to large windows/exterior wall. My central air is setup such that I can turn on the basement fan (on low) and it pulls from the Cold Air Return in the vault above the stove. So it draws this heat down into the basement and keeps the basement ~60deg. Main and upstairs stay ~65deg with the exception of Master Bed/Bath where we use an oil radiant heater.

Considering this, I realize the stove does awesome. I had hoped that the main and upstairs would be warmer but even riding it out on max nearly all the time, it just doesn't get above 65 - even in the same room as the stove.

I learned the hard way this morning that my stove needs an Outside Air Kit. My downstairs central air kicked on (on high) and started pulling through the cold air return above the stove. We woke up to the smell of smoke in our living room. So, it's very likely that adding the OAK will improve efficiency more. I had hoped that with the larger home it wouldn't really be needed. I was proven wrong. Now I just have to figure out how I want to plumb this thing...

One other thing to look for. On mine, the cat thermostat/probe hits the fins (mines an Ultra). When it gets hot, the need hits the fins and will 'pop' the probe out a bit. I think this creates a direct path of air to the catalyst. Besides being annoying, I think it can be damaging to the cat to have that direct path of cold air. Check for this. If yours does this, just rotate the probe dial CCW so the '0' point is right next to the fin on the left to give it a little more margin. Hopefully that makes sense. There's a forum on here where we were talking about it last year and I'm pretty sure there's some pics.

I know this doesn't necessarily resolve your concern but maybe gives you a couple things to look at.

 

[begreen]

Yes it's a basement install... I have fresh air kit hooked up to it c if it would make it any better it didn't I don't think. Pipe comes off stove goes to 90 thru wall then another 90 up side of house not quite for sure how high it is. Thinking probably 20 feet high from the exit to wall going up

Basement installs can be troublesome for draft. Make sure there's no leakage upstairs from open or leaky windows, attic access door, etc..If there are competing appliances or exhaust vents then outside air may be a necessity. Sometimes softening the hard 90 above the stove with a pair or 45's helps too. Also be sure that the horiz. section is a short as possible and heading uphill toward the chimney.

 

[jetsam]

Yes it's a basement install... I have fresh air kit hooked up to it c if it would make it any better it didn't I don't think. Pipe comes off stove goes to 90 thru wall then another 90 up side of house not quite for sure how high it is. Thinking probably 20 feet high from the exit to wall going up

You should put up some pictures of the install for the guys to look at... you could have a safety issue with that OAK. Take a peek at this from the 2015 BK thread -> https://www.hearth.com/talk/threads...rformance-thread-everything-bk.145814/page-59

 

[studdriver_40]

Thanks for the help guys and I will do so with some pictures tomorrow for u once it's day light. I just thought the oak would give it fresh air easier to burn than warm air. Give it better performance. My pipe going thru wall is not facing up hill flush as can be so I can run my pipe up straight. I had it all inspected and passed according to the guy that inspected it

 

[studdriver_40]

Also the wood moisture is 20 or less. It's like I have it wide open and acts as if it's on a lower setting med range u know.

 

[begreen]

Also the wood moisture is 20 or less. It's like I have it wide open and acts as if it's on a lower setting med range u know.

So is there an OAK currently connected to the stove? Also, is there a chimney cap screen and if yes, when was the last time it was cleaned?

 

[lsucet]

Another thing to look is, that the thermostat knob is calibrated like it should. Be sure that it stop wide open right at 6 o'clock. If it goes further than 6 o'clock too much you need to calibrate it.

 

[Poindexter]

I think the op is getting some good help here, not trying to take away from good advice.

I can see one simple thing to check that has only been mentioned once.

When the stove is cold, open the loading door, take the flame shield down, and take some pictures (use flash) of the face of the combustor.

I am not saying it is or isnt, but this sounds real similar to the symptoms i was seeing when i had a bunch of fly ash on the face of my cat. If you get a little gentle snow fall of fine grey ash when the flame shield comes out skip the photos, use a vac atyachment with the bristles on it to gently vaccuum the face of the combustor and try burning the stove again before you go through all that OAK agony.

 

[black smoke signals]

My understanding is that the thermostat will self-protect the stove from overheating.

Just trying to understand self-protect? When the stove is overheating does the t-stat have a spring inside that over rides and slams the t-stat shut and will the t-stat have to be reset for the next fire?

 

[lsucet]

Just trying to understand self-protect? When the stove is overheating does the t-stat have a spring inside that over rides and slams the t-stat shut and will the t-stat have to be reset for the next fire?

It is more simple than that. Including at high burn rates the thermostat closed enough to avoid an overfire condition. There is no reset process or nothing at your end that needs to be done, except of finding the burn rate that keep you warm and satisfy your comfort. The spring coil react to the calibrated temperatures set by manufacturer. Just find the sweet spot that you are getting the heat need it and the thermostat will do the rest.

 

[lsucet]

On reload follow the procedures in the manual. open the air, bypass, door, reload, burn it for awhile on high, etc. the manual tells you exactly how to do it depending on the situation. STARTING A FIRE, RELOADING CAT INTO THE ACTIVE ZONE, RELOADING WITH INACTIVE CAT, ETC.

 

[Highbeam]

Just trying to understand self-protect? When the stove is overheating does the t-stat have a spring inside that over rides and slams the t-stat shut and will the t-stat have to be reset for the next fire?

The bimettalic spring of the thermostat will always dial back the intake to maintain stove temps in a safe range. This is because the maximum thermostat setting is set to provide this safety feature. It won't slam shut but work as normal to regulate the temperature at the predetermined max.

Now if your door glass is broken or some other source of combustion air is available then the thermostat has been defeated and you can overfire the stove.