Unable to keep the fire running full - Princess32

[Phalynx]

New to the whole wood stove world and having trouble staying warm. We have about 800 sq ft house 1 1/2 story loft with a Princess 32 in the middle. It’s getting really cold outside (-24F) and we’re running it wide open and just can’t keep the place warm. It’s currently 55F in here. House has R21 walls, R30 roof, r35 floor. The stove pipe is about 19’ total length. It is a straight up run and is about 1’ over the ridge. It doesn’t appear to have any draft issues. I almost never have smoke come back in when I open the door. I am mostly burning birch. Moisture is between 14-18%. We are hot loading it a bunch to try and keep the temps up in here but we also get a lot of coaling building up on the bottom until almost level with the bottom of the door. We can get the fire roaring at times where the probe is at 6 o’clock but it usually hands in the 3-4 o’clock range. We are running it wide open. If we turn it down, the fire will go down to right at go/no go zone.

What can I do differently? What am I possibly doing wrong? I need more heat in here. I did let the fire go completely out and clean out the box, I inspected the stove pipe, it looked pretty clean with just a little bit of creosote but mostly clean pipes. I vacuumed the cat which was about 1/2 clogged (probably from burning wet wood at the beginning of the season). The bypass is clean. Let me know if there’s anything else I need to mention?

Thanks

 

[stoveliker]

I think you have too much draft, and heat is sucked up the flue. (And ashes in the cat).
You need a key damper.

Your wood may also be too wet (coals left over).
Are you measuring after letting the wood get up to temp for a day,.then resplitting and measuring on the freshly exposed surface (pins as deep as possible and parallel to the grain,)?

 

[Murray01]

Are you closing the Bypass door and feeling/forcing the “snap” when it closes? I’m assuming you are running the stove as per the owner’s manual?

 

[moresnow]

Factory fans installed and running?

 

[EatenByLimestone]

Is the stove hot enough?

 

[Phalynx]

Your wood may also be too wet (coals left over).
Are you measuring after letting the wood get up to temp for a day,.then resplitting and measuring on the freshly exposed surface (pins as deep as possible and parallel to the grain,)?

I just split some and checked it. They are between 16.8% and 19.9% on the various sticks I split and checked.

Are you closing the Bypass door and feeling/forcing the “snap” when it closes? I’m assuming you are running the stove as per the owner’s manual?

Yes, I can feel the door mechanically lock closed.

Factory fans installed and running?

There are no fans installed and no fresh air intake at this time. We do have 2 stove top fans running. I understood the factory fans to do the exact thing as the stove top.

Is the stove hot enough?

We can get it to 450-500F regularly, but not more for very long.

Also, another issue seems to be that the coals on the front of the stove get oxygen but those in the back don’t. The front glows, the back is very dark to black. You might be able to see in the picture. We don’t have a lot of wood in it at the moment as we’re deciding to empty all the coals or not at the moment.

 

[stoveliker]

Do you have a flue probe?

If your draft is too high, you can get ashes sucked into the cat, clogging it, leading to anemic performance.

Would it burn ok after vacuuming the cat (and taking the pipe off, shining a light back there and seeing that all channels are clear? - taking the cat out you'd need a new gasket to put in t back in).

 

[EatenByLimestone]

You need to run the stove warmer too. The stove isn’t putting out enough btus at 450 to heat the place at those temps. Try it at 650.

Rake the coals forward when you reload. The air hitting them (bright red) will burn them down so they don’t fill up the stove.

If you have a ceiling fan, turn it on to circulate the air.

 

[Phalynx]

Do you have a flue probe?

If your draft is too high, you can get ashes sucked into the cat, clogging it, leading to anemic performance.

Would it burn ok after vacuuming the cat (and taking the pipe off, shining a light back there and seeing that all channels are clear? - taking the cat out you'd need a new gasket to put in t back in).

I don’t have a flue probe but 2 weeks ago, we inspected the pipe and vacuumed the cat from the front (I didn’t realize it was 4” deep so it might have more in it). After vacuuming it burned much hotter and better for a week or so. Here are a couple of pictures. The stove pipe and the strange “oxygen” pattern when the door is closed vs open. When closed with the damper fully open and the cat either bypassed or open, the back doesn’t seem to burn but the front does. Open the door with the cat bypassed and the entire coalbed lights up with happiness.

 

[Phalynx]

You need to run the stove warmer too. The stove isn’t putting out enough btus at 450 to heat the place at those temps. Try it at 650.

Rake the coals forward when you reload. The air hitting them (bright red) will burn them down so they don’t fill up the stove.

If you have a ceiling fan, turn it on to circulate the air.

I can’t get it to burn any hotter. That’s the main issue. I have raked the coals forward and loaded wood to the back, That wood just chars and doesn’t really burn unless it comes forward. Ceiling fan is on full. We have a temp sensor at the top of the loft an down stairs so we know how much heat it up there.

 

[stoveliker]

The fact that after vacuuming it burned hotter is consistent with having too much draft.
Clean the passages,.and you get good burns. Then soon you end up with anemic performance again.

19 ft straight up is not much but with -20s F outside I think you have too much draft, quickly clogging up the cat, leading to the cat stalling, ending up with coals.
And when you open the door it is with the bypass open,.so no smoke rolling out because the draft immediately picks up as you bypass the clogged cat.

That's my $0.02

 

[Phalynx]

So I need a stove pipe draft control?

 

[stoveliker]

That would be my suggestion indeed.
Your draft will vary hugely anyway between 32 F and -20 F, and a key damper in the pipe will help you dial it down to similar values.

 

[Quirke]

While sounds like your draft is likely too strong, one more piece of information that might be useful in diagnosing your situation is your burn time on a full load.

Is the stove eating wood and sending the heat up the flue? Or is the thermostat throttling down the burn rate, requiring the factory fan kit to help extract heat from the stove and allow it to provide more air/oxygen to the fuel?

You could try using a box or pedestal fan directed at the stove to help transfer heat from the stove to the room and see if that has a noticeable effect.

 

[Phalynx]

Burn time is not very long at all. A full load will burn maybe 4-6 hours. I did try a fan in the back but it didn’t seem to help. I am going to try a fan again to see though.

 

[stoveliker]

But that's with coals (and thus burn time) left

While a key damper is cheap, you may benefit from a manometer to measure the draft (and so you can dial in your key damper based onto the draft you have).

 

[Highbeam]

The fuel will always burn front to back. That’s because all combustion air comes from the air wash in the front glass. When properly loaded, full, you can’t see the back until the front burns away.

You can shove your cell phone up in front of the catalyst and take a picture looking into the cells to verify whether it’s clogged. Sure sounds like it. If so, you can sometimes blow it out or vacuum it out in place. Don’t remove the cat without a new gasket.

You can only check moisture content on room temperature wood. Cold wood reads falsely dry.

Do you have a bird screen on the cap? Those things clog up fast and ruin your burn.

 

[Highbeam]

Burn time is not very long at all. A full load will burn maybe 4-6 hours. I did try a fan in the back but it didn’t seem to help. I am going to try a fan again to see though.

Don’t worry about the fans. Sure they help but are not terribly important. You’ve got something else going on.

 

[Todd]

What does your cat probe read? Is it glowing red? If so that means it should be over 1000 degrees and working as should.

 

[moresnow]

I did try a fan in the back but it didn’t seem to help.

Placing a fan behind the stove is likely to give you unfavorable results. The stove takes its combustion air in from the rear. The fan behind the stove seems to reduce burn time from my experience. Placing a small desktop fan in a cold room gently blowing cool floor air towards the stove seems to help spread the heat nicely. Worth a try.

No BK should be sold without the factory fan kit IMO. It truly makes a very significant difference in heat dispersion. Critical in colder parts of the world. Alaska qualifies as being cold

 

[m37charlie]

I’m just south of you on the Turnagain Arm bluff in S Anchorage. Yes, this is a long cold spell for the 21st century.
I’m heating 2 floors x 1150 sq ft each in a Lindal house with a 35 yo King. Respite comes only from 11am till sunset just before 4 with brilliant sun reflecting off snow and ice to the south.
I have lots and lots of wood due to arrangement with a tree service.
Anyway, I’ve found over the years that it’s best to fill up completely with birch right at bedtime. Lately I’ve been setting air inlet control at about 2.2-2.3. I come downstairs 6-7 hours later and cat is still glowing.
To get rid of the great big birch coals, you need to burn dry spruce all the rest of the day. That way, even in a cold period like this, I only need to dig out ashes every 3-4 weeks. And there’s almost no unburned coals in the bucket.
And…I have 3 Ecofsns running, plus my automatic Inkbird controlled on-off system for the BK fan, always on in quietest setting, goes own when fsn air plenum hits 126F, off at 123F. Completely automatic.
Fans really do help.
My recent gas bill was 4.4ccf/day, with garage thermostat at 40F, basement thermostat at 60F, and 1 out of 2 (north side) upstairs zones at 68F because daughter was staying with me.
Burn spruce except when sleeping to avoid rapid birch coal buildup, they all will burn away during the day.

 

[Phalynx]

I talked to my dealer today about all the options and thoughts about the problems. In the end, I was told, and I believe him, that it is operating at max. I did just remove my catalyst and completely clean (carefully) and replaced with new gasket. He said the sad truth is that the best wood we have in Alaska is the best of the worst allowable wood in the world to burn. Birch just isn’t that dense and when it’s -32F outside, 4-6 hour burn times is all you’ll get at max with birch. He said a damper is a horrible idea and will cause serious issues and that the Blaze Kings essentially have all the damper you need. He agreed about using a fan on the box to extract all the heat you can get from it. And he showed everywhere I need to check and clean.

He mentioned we get clinkers all the time here because the Birch burns so fast that the coals just fall on the older coals and insulate them so shoveling out the firebox every 3-4 days may be required when it’s this cold out. Right now we’re at 5F, which feels like summer but we’re expected to get back to -30ish in the next couple of days so I’ll report back how the performance is doing.

He said burning these stoves hot is what they need and they’ll burn as clean as they can be. You’ll have the cleanest glass on the front when you do and I agree, the glass is nicely clean.

 

[Phalynx]

Burn spruce except when sleeping to avoid rapid birch coal buildup, they all will burn away during the day.

That is some good information. I’ll give that a shot too.

 

[m37charlie]

Like I said yesterday, if you just use birch to get a good night sleep and then (dry) spruce the rest of the day, you won’t get “clinker” buildup.

 

[stoveliker]

I'm sorry, but the dealer is, in some aspects, wrong.

Clinkers happen when you burn hit because of ashes with high mineral content fusing. Nothing to do with coals.

More of importantly, he's wrong about the damper.
The damping that BK stoves provide is a squeezing on the input of air. The amount coming in can be tuned from max to some (EPA) minimum. However, that max is determined by how hard the flue sucks on the stove. That is the draft.
At -30, that draft is high. In fact it is almost certainly higher than th breast range the stove was designed for and tested with.

I believe him if he measured the draft on a hot stove at -30. Which he didn't, but a good dealer should. They are designed for a certain range of drafts, and you're most likely outside of the design parameters. A damper can help get back in that range.

A damper will cut that suction, and as a result cut the amount of flow, leaving more heat transfer to the room.

That said, it's hard to judge btu needs from here, so maybe the stove is not able to provide what you need even with a damper.