Woodstock Absolute Steel - How to burn hot?

I got my new Woodstock AS delivered and hooked up a few days ago (thanks to all the advice on my previous posts!), and I've been really impressed with its long slow burn performance so far. A relatively small load with the cat engaged and the draft set between 1 and 2 can produce hours of steady heat with STT around 300 or so, and no visible flames or glow in the firebox.

I'm confused, however, about how to get a hot fire going in this stove. The operating manual warns against overfiring,with STTs above 700 for prolonged periods, and I've read other posts here where people describe steady STTs well over 500. Yet I've been unable to get the STT much above 400, or get much in the way of secondary flames even with the draft control set at 4 and the cat lever open or closed.

I don't necessarily need to run the stove really hot for heating my house (at least while temps outside are in the 40s), but I would like to crank it up long enough to burn off the layer of black gunk that has turned my glass almost fully opaque!

Is it necessary to pack the AS's firebox really full to get the temps up high? I've put decent sized loads, but not yet tried a really tight pack.

I also wonder if I've got sufficient draft to really fire this stove. With my old, poorly sealed and crumbling firebox VC Resolute Acclaim, I could throw a few sticks on a hot bed of coals, close the door and open the damper all the way, and in 10 or 15 minutes I'd have a roaring inferno, with STTs pushing 750. With this stove, I've struggled to get new logs on a hot coal bed to ignite without leaving the door cracked open, and closing the door before they're all vigorously burning and the STT is comfortably over 250 tends to snuff out the flames and prevent the cat from reaching sufficient temperature to ignite.

I'd appreciate any advice from seasoned Woodstock owners who know how to bring the heat.

 

I question fuel also, as my Ideal Steel, load box, get to temp, 650 comes right fast. I do have good draft!

In fact, when loading its a race to fill stove, usually 3 rows high NS, 5 pieces wide, with 2 pieces EW on top. Before its fully engulfed.

 

My firewood is probably a bit underseasoned (barely a year since being split), but I've also tried mixing it with Canawick and Lewis Bricks to lower the average moisture content of a load, and even loading it only with those very dry bricks. That's part of the reason I suspect draft over fuel issues. Also, the firewood quality was no better with my old stove, in which overfiring was a constant risk.

 

I agree, wet wood or poor draft. Is there a clean out on the chimney that’s been left open by chance? That will kill it quickly, as will any other breech in the flu.

 

I checked the cleanout door... it's probably not totally airtight, but it's closed and doesn't show any obvious gaps. I'll pick up a bundle of kiln dried wood to see how that performs, but given that the super-dry sawdust bricks aren't burning much hotter, I suspect draft issues (reduced air intake on tighter EPA stove, plus switch to rear vent, on a chimney that was maybe borderline weak draft to begin with?).

 

I should also add, I may be overlooking something really obvious... I only realized after 3 days of burning that the ash was piling up so high in the firebox because the ash pan came installed with its cover in place!

 

FeelTheBurn .. Not trying to be smart.. But grab another thermometer also. I have never used saw dust brick, but I have used KD furniture scraps, walnut, cherry and maple.. Outside no chimney/ draft at all, got 300 to 500 No problem

 

Thank you FeelTheBurn for posting this. I too am a new AS owner and am having similar problems. I get great secondary burn, but have only seen the CAT glowing once when I lifted the lid. Mine seems to run the best at the air set to 1.8 for long burns.
I just had the chimney professionally inspected and cleaned. Passed with flying colors.
Don't think it is my wood. Two year on the seasoning with 60% being ash. The highest mm reading I have found is 20.1 on the Honey Locus. Most of it is running low to mid 19s. Like you, I am thinking about getting a firebox full of that $1000/cord wood from the supermarket to put that possibility to rest before I call Woodstock.
My problem appears to be incoming air or CAT problem. I have had the CAT out and it is not clogged. About ready to tear it a part and see what the other end the air lever does. Crack the door and I have a great fire.
I hope you don't mind me tagging along, but mine is new also displaying the same symptoms. Maybe Woodstock had a production problem.

 

Good advice, CbVT, but I've got the old stove's thermometer on the stove pipe, the new thermometer that came with the AS on the cover plate over the top vent opening, and I've been compulsively cross referencing these with infrared thermometer gun readings taken at all stages of burn and all surfaces of the stove. The hottest I've been able to get the exterior of the stove is about 500 degrees, measured with the IR gun at the glass and on the side opposite the door (about where the screw for the cat probe is located). The IR temp generally corroborates what the magnet thermometers are reading at the stove pipe and top vent cover, and it barely measures much above 400 anywhere on the stove top and 300 on the short section of stove pipe, even with a fully ignited load of 5 or 6 saw dust bricks after at 30-45 minutes with the damper set at 4.

I still need to add a cat probe (and ideally some remote monitoring solution) to satisfy my obsession with knowing the temperature everywhere at all times!

 

Hey Marshel, glad to hear it's not just me! It definitely feels like an incoming air issue, because everything flares up nicely once I open the door and leave it cracked. As soon as I close the door, though, any flames quickly snuff out, and the glow from the coals rapidly fades. I don't think it's a negative pressure situation either, as our house is still fairly leaky (confirmed with a blower door test done after sprayfoaming the basement a month or so ago), and the issues appeared even the first couple days when I was burning with the windows open while the paint was curing and stinking up the house.

 

FeelTheBurn ... I have no experience with AS..

 

It is likely draft and/or dryness of wood. There isn’t really anything to go wrong on the AS air control. What happens when you leave the air wide open?

{edit: we ran the AS a full season as a beta-tester}

 

Awful short on seasoning time. Gotta wonder what MC is. Unless I missed it?

 

Here’s the PH coming up to temp. Bypass open, air at half. Flu probe at 500.

It is easier to hit the higher temps by taking a run at it rather than easing into it.

Ok, flu hit 600 and I closed the bypass but didn’t touch the air.


Flu at 650, stove top at 400.

Five minutes later, 625 flu, 430 STT.

Going to start cutting air now (warm out, and I don’t want 550 stove top).

Air mostly closed, flu damper half-closed (strong draft here)

 

Ok. Here are my running stats for the night.
Loaded all up about an hour and 15 ago. Air opened all the way.Engaged CAT after STT 400 and load was completely charred over. Plenty of flame and eventfully good secondary burn.
15 minutes later turned the air down 4 clicks.
Turned air down another 4 clicks after another 15 minutes. A little less flame but still good secondary burn.
4 clicks down 15 minutes later. Not much change.
Another 4 clicks down after 15 minutes. Less flame good secondaries and plenty of heat.
Down another 4 clicks. What I believe you call ghost flames. Occasional flames beautifully dancing around on secondarys. Lifted the lid and CAT is glowing red. That is a rare occasion. Presently at about 1.8 on the inlet air. Plenty of heat in my chair 8 feet away. SST 475* CAT probe 900*. Outside temp. 23*. Coldest it has been since installing the AS. If it continues to perform like this I believe I will be satisfied.
The colder the outside temperature is the better the thing appears to perform. Still trying to learn. Tonight is the best performance that I have had. What did I do? Don't know for sure except slowly reduce intake air and the CAT is burning. I will have to figure out what makes the CAT burn.
Picture of my present burn.

 

Leaving the damper set at 4 doesn't do much. I need to keep the door open until the wood is fully engulfed by flame, or else whatever flames do get started snuff out when I close the door. Once everything is burning thoroughly, I can close the door and leave the damper at 4, but the stove top temp still barely gets above 400.

The dryness of my split wood is certainly suspect, and I plan to grab a bundle of kiln dried wood to see what difference that makes. But even burning exclusively with Canawick or Lewis bricks (extremely low moisture compressed sawdust), I still get the same effect.

Also, I've noticed that a rolled newspaper lit and held toward the top front of the cold stove will slowly burn down and send smoke up into the flue, but it doesn't get sucked up and burn down nearly as vigorously as with my old stove. This leads me to believe the issue is a draft difference either in the air path from the firebox to the rear vent, or in the stovepipe from the stove to the chimney.

 

Dunno. But it sure looks like you did "something" just right! May just be giving it plenty of warm up time before backing it down. Pics look great!

 

A little bit later, STT 460, flu probe 580.

 

Nice! I have no doubt the Woodstocks can burn hot. Just need to figure out why mine won't. I suspect draft issues but will also test with some really dry wood when I have a chance to pick some up.