Blaze king problems. Short burns

[Jesse83]

I recently installed a new blaze king princess insert and I'm getting short burn times. I haven't been impressed with this stove at all.
I'll stuff it full of maple/fir and it's completely out within 8hrs. I could get longer burns out of my non cat stove. I've checked the door gasket doing the dollar bill test and it past. Any other suggestions?
Little info on my usage.. It's a 17' insulated liner. Load the stove up get it nice and hot activate the cat then eventually turn it to the lowest setting. And it's out within 8hrs. Its usually in the 30's to 40's outside. I'm having a hard time keeping the house warm. Its a 1,400 sqft house. Is this normal or did I get a defective stove?
Thanks for any input.

 

[begreen]

Doesn't sound right. In those temps BK owners say they're seeing 16-24 hr burns.

 

[webby3650]

You say gradually turn the stove down. Have you tried getting the stove going, shutting the bypass as soon as the cat is active, then turning the tstat to medium or so? I see very little reason to shut the stove down in little increments with good seasoned wood.

Are you leaving a good bed of ashes in the stove? Some folks mistakenly shovel out and restart a fire each time, rather than leaving the ashes in there and loading more wood in on coals.

 

[SuperJ]

Sounds odd. This might sound ridiculous but are you sure your not operating the bypass handle backwards?
Can you see anything coming out your chimney a couple hours into the burn.
Do you have a moisture meter for your wood? Good wood has enough btus in it that an 8hr burn in the princess should be really hot. Especially if it’s 30-40f outside.

Do you have some pictures of your stove and chimney?

 

[Jesse83]

Yes most times I have a nice sized bed of coals. Depending on how cold the house is after I activate the cat i leave it on high or I set it to medium. Other times I'll just turn it to low. The one thing I have noticed when on the lowest setting occasionally I do see the wood flare up. I was under the impression that a cat stove on the lowest setting shouldn't have a flame is this correct?
I'll upload a pic of the stove. I'll try to get one of the chimney tomorrow. It's a 6" factory insulated duraliner inside a masonry chimney.

 

[Jesse83]

Yes on the by pass. At least I'm pretty sure lol. Handle up for by pass and down to activate the cat.

 

[Poindexter]

Well, it could be that you joined the club of those of us who got our fuel "too dry." You don't win anything for joining the club, maybe when we get up to a dozen members or so we'll make a club patch. I think you'd be number 5...

In general the stove makers (NASPA? NASxx? whatever national group) has figgered out "most" woodburners have fuel MC (moisture content) around 20%. So wood stoves are made to operate at or near 20%MC, and that same 20% MC is specified for EPA testing.

The sweet spot for my stove, my install is actually 12-16%MC. I did burn several cords with single digit MC not that long ago and my burn times were in the toilet.

Here is what you do. Bring 3 or 5, heck, bring 6 splits if you are totally into overkill from the yard into the garage for 48 hours. Go high, middle and low on your woodpile. Get some fat ones. Leave them be for 48 hours. Some folks will say 24 hours is enough, but I am not one of them. So you bring in five fat splits tomorrow after work, Thursday night. Saturday afternoon split them open, and then measure the MC on the freshly exposed surface that was inside the piece of wood a moment ago. Put the pins in parallel to the grain.

If you find single digit MC inside there, or 10% or 11%, you are in the club, your wood is too dry. Welcome to the club. Get hold of your local BK dealer and get some hand holding. Mine treated me right and got me through the season without melting anything.

If you find 12-16% in those splits, try this. Open the loading door with the combustor bypassed and the Thermostat turned as high as it will go. Stuff the firebox to the gills with fresh splits on your hot coals. Hold the loading door open just a crack for 20 to 30 seconds. Close the loading door. Wait 20 to 30 seconds. Turn the thermostat down to the top of the swoosh or the highest labeled number. Engage the combustor. Wait 20 minutes. Turn the Tstat down to about 1/3 of total labeled throttle all at once in one step, no screwing around. Measure your burn time.

FWIW with engaged combustor I can burn a load of 12%MC spruce down to hot coals in 4 hours if I need the heat, but I can also get 35 hours out of the same load (Ashford 30) if I don't.

I think the Princess insert has a smaller firebox, so YMMV, but it could be you are in the club.

 

[Blazing]

Well, it could be that you joined the club of those of us who got our fuel "too dry." You don't win anything for joining the club, maybe when we get up to a dozen members or so we'll make a club patch. I think you'd be number 5...

In general the stove makers (NASPA? NASxx? whatever national group) has figgered out "most" woodburners have fuel MC (moisture content) around 20%. So wood stoves are made to operate at or near 20%MC, and that same 20% MC is specified for EPA testing.

The sweet spot for my stove, my install is actually 12-16%MC. I did burn several cords with single digit MC not that long ago and my burn times were in the toilet.

Here is what you do. Bring 3 or 5, heck, bring 6 splits if you are totally into overkill from the yard into the garage for 48 hours. Go high, middle and low on your woodpile. Get some fat ones. Leave them be for 48 hours. Some folks will say 24 hours is enough, but I am not one of them. So you bring in five fat splits tomorrow after work, Thursday night. Saturday afternoon split them open, and then measure the MC on the freshly exposed surface that was inside the piece of wood a moment ago. Put the pins in parallel to the grain.

If you find single digit MC inside there, or 10% or 11%, you are in the club, your wood is too dry. Welcome to the club. Get hold of your local BK dealer and get some hand holding. Mine treated me right and got me through the season without melting anything.

If you find 12-16% in those splits, try this. Open the loading door with the combustor bypassed and the Thermostat turned as high as it will go. Stuff the firebox to the gills with fresh splits on your hot coals. Hold the loading door open just a crack for 20 to 30 seconds. Close the loading door. Wait 20 to 30 seconds. Turn the thermostat down to the top of the swoosh or the highest labeled number. Engage the combustor. Wait 20 minutes. Turn the Tstat down to about 1/3 of total labeled throttle all at once in one step, no screwing around. Measure your burn time.

FWIW with engaged combustor I can burn a load of 12%MC spruce down to hot coals in 4 hours if I need the heat, but I can also get 35 hours out of the same load (Ashford 30) if I don't.

I think the Princess insert has a smaller firebox, so YMMV, but it could be you are in the club.

I've got some oak that puts me in the club I use it for cold starts. I also helped a fellow member as did you with wood that was under spec. Tell tail sign for my stove was black smoke even with a combustor well into the active zone.

 

[Highbeam]

For long burn times you need to tightly pack wood to fully fill the box.

 

[jetsam]

The one thing I have noticed when on the lowest setting occasionally I do see the wood flare up. I was under the impression that a cat stove on the lowest setting shouldn't have a flame is this correct?

No; the thermostat opens up the air when the stove gets too cold. If it opens up enough, you get flames. In 30-40 degree weather, expect flames.

If your stove is operating properly, and you're confused about where yout long burn time is, I expect that you are following the manual and putting the fan on whenever the stove is burning.

In my experience, 10 hours is about the most you can hope for with the fan on; more than double that with the fan off. Why would it make such a huge difference? Because the fan blows right over the top of the cat and firebox. The firebox cools, the thermostat calls for more air, the wood burns faster.

I don't use the fan when it's mid-40s or higher because I like the super long burn times and don't need that much heat. When I need more heat, fan goes on, house warms up. My overnight winter burn is medium thermostat, lowest fan.

I am a little puzzled about you having a hard time heating 1400sf with that stove though... mine does almost double that.

Here's my suggestions:

1) Try a load without the fan if it's 40 out.
2) Speed up your loads. Put the new wood in, give it a minute, close the bypass, set the thermostat where you want it. No long waits while the wood blazes up the chimney (unless the stove started cold, which is a foreign idea to my princess insert... I have started one fire so far this winter.)

 

[Poindexter]

In my experience, 10 hours is about the most you can hope for with the fan on; more than double that with the fan off. Why would it make such a huge difference? Because the fan blows right over the top of the cat and firebox. The firebox cools, the thermostat calls for more air, the wood burns faster.

Well done sir! For me to burn down a box full of spruce in four hours, tstat is on high and the deck fans are running WOT (wide open throttle). To get 35 hours out of the same load, deck fans are off and the tstat at is at the pointy end of the swoosh.

You got a really nice summation in there that fits my observed data perfectly.

 

[jetsam]

Well done sir! For me to burn down a box full of spruce in four hours, tstat is on high and the deck fans are running WOT (wide open throttle). To get 35 hours out of the same load, deck fans are off and the tstat at is at the pointy end of the swoosh.

You got a really nice summation in there that fits my observed data perfectly.

It's simple, but it actually took me a while to get it figured out. I get a lot more out of my stove now.

Hmm, speaking of my first year with the stove... one thing that was terrible about it was the installation, which I stupidly paid a stove installer to do. No insulation on the exterior masonry, no liner insulation, and no blockoff plate...

If the OP has no blockoff plate and a poor seal on the surround, that would also go a long way towards explaining the heat problem.

 

[weatherguy]

I wouldn't expect the burn times the free standers get, I could get 12 hours out of mine, 10 if it was colder out, could even burn a full load in 8 hours if I needed the heat but I got a ton of heat in a house twice the size of yours. Takes a while to get the feel of how to burn your stove in your setup best.

 

[begreen]

In my experience, 10 hours is about the most you can hope for with the fan on; more than double that with the fan off. Why would it make such a huge difference? Because the fan blows right over the top of the cat and firebox. The firebox cools, the thermostat calls for more air, the wood burns faster.

I don't use the fan when it's mid-40s or higher because I like the super long burn times and don't need that much heat. When I need more heat, fan goes on, house warms up. My overnight winter burn is medium thermostat, lowest fan.

Thanks for the candid assessment. Good info.

 

[Tar12]

Yes on the by pass. At least I'm pretty sure lol. Handle up for by pass and down to activate the cat.

Are you closing the by pass handle until you hear a click?

 

[yooper08]

As jetsam alluded to, cat stoves like a BK can go for really long burns, but when the heat is needed on cold days, they're going to burn more like a non-cat, at least in terms of time. Cat stoves have a much wider range of burn times just due to how they work versus a non-cat. I haven't operated one, but my assumption is that burn times are essentially on an exponential decay type trend, where smaller adjustments to increase heat near the long-burn settings have a bigger impact on time and further adjustments from there start to have smaller impacts until we get to non-cat-like operation.

 

[black smoke signals]

I’m curious why in the picture your convection deck is missing?

 

[jetsam]

I’m curious why in the picture your convection deck is missing?

Oh yeah. You can't get that stove without it either, as far as I know.

Good spot!

Never mind all that stuff about the fan, then. :\

Here's my new guess: No blockoff plate, and 75% of the stove's heat output is going up the chimney because of that weird shroud that is blocking almost the entire convection deck's output and sending it up the chimney.

Also visible are large airspaces on the left and maybe right side; if there's no blockoff plate, that's another serious issue.

I wouldn't like to try to heat a house with that setup, but a blockoff plate would fix a lot of what's wrong with it. (A blockoff plate, tin snips, and a bundle of Roxul would fix all of it, and that's about $60 in parts and tools.)

 

[SuperJ]

Remember that block off and insulation are two different things. Insulation just insulates, it doesn't prevent infiltration/exflitration.

 

[Jesse83]

The picture was taken before everything was complete. It has the convection deck on it now. The block out plate is also installed right where the pipe enters the chimney so no air can escape from the house up the old chimney out of the house. The top is also sealed. The only way for air to go would be through the stove burned and up the chimney. As for the shroud that comes factory on an insert. It's there to cover the opening of the fireplace.
I've tried running the stove without the fan running and I noticed the stove does get hotter and the wood burns faster. If I turn the fan on medium the wood seams to last longer.
Should the cat temps stay the same? Seams like mine temp jumps around even with no change of the thermostat or fan speed.

 

[jetsam]

Well, the blockoff plate theory sounded good.

Thermostat settings bring equal, the load will burn faster with the fan on. Not a little faster, but maybe twice as fast at low fan, and more so at higher fan settings. It does not scale linearly, as the thermostat can only open the air flapper so much above the baseline created by your dial setting. (Though as you continue increasing fan speed without increasing the thermostat setting, you will eventually cool the cat too much, and take a severe performance hit.)

Your cat temp will vary if you don't touch the controls. It'll be higher at the start of the load while the wood is offgassing (as long as it's active), and then taper off as its fuel gets depleted. If you're watching the dial (there is no need to), it probably also jogs up and down a little as the thermostat adjusts the air.

I don't even have a theory to explain longer burn times with the fan on. Even if the stove had a major air leak, the fan setting wouldn't increase burn time (and we'd already know about it because your first post would have been "help with raging uncontrollable inferno stove").

At low burn rates with medium fan, you could definitely cool the cat into inactivity, which would explain poor burn times and heat output. If the cat thermometer is near the inactive zone, it needs more thermostat or less fan (or more wood).

 

[Rickb]

The picture was taken before everything was complete. It has the convection deck on it now. The block out plate is also installed right where the pipe enters the chimney so no air can escape from the house up the old chimney out of the house. The top is also sealed. The only way for air to go would be through the stove burned and up the chimney. As for the shroud that comes factory on an insert. It's there to cover the opening of the fireplace.
I've tried running the stove without the fan running and I noticed the stove does get hotter and the wood burns faster. If I turn the fan on medium the wood seams to last longer.
Should the cat temps stay the same? Seams like mine temp jumps around even with no change of the thermostat or fan speed.

This makes no sense unless the thermostat is backwards.....

 

[Jesse83]

Thanks jetsam. I'm wondering if it's my wood quality then. Like Poindexter said maybe the wood is too dry. I have no way of testing it. If there was a gasket problem or chimney problem the fire would be raging correct?

 

[black smoke signals]

Thanks jetsam. I'm wondering if it's my wood quality then. Like Poindexter said maybe the wood is too dry. I have no way of testing it. If there was a gasket problem or chimney problem the fire would be raging correct?

Pointdexter is spot on your wood MC needs to be checked too but if your wood was to dry I don’t think you would get a 8hr burn I never could (thanks blazing) I would like to say you did all the right things setting up your insert. When you state your t/stat goes up and down can you express this in o’clock? My experience with my cat was using the wrong MC wood often seeing 6 o’clock temperature it finally failed after 8 months. There are a lot of good people here to help you I would like to see this problem of yours sorted out.

 

[black smoke signals]

Dollar bill check your bypass too