Hearthstone vs Progress, bee in bonnet

[fire_man]

Maybe we are getting twisted on the words "thermostatically controlled".

I think when WS says "The secondary combustion system engages as exhaust temperatures reach about 1000 degrees F" they are referring to the ignition temperature when the gases naturally ignite. This would agree closely with my experience, when the stovetop reaches 500ºF the firebox ignites and the rule of thumb per WS is the stovetop is about half the internal firebox temp.

AI Overview
Wood smoke gases ignite at varying temperatures, but generally, the flammable gases (like methane, methanol) released during wood's gassification (around 500-700°F) need sufficient oxygen and temperatures of at least 1100°F (600°C) in the firebox for clean, complete combustion (secondary combustion) to burn those gases efficiently, though the initial wood ignition starts lower, around 400-600°F, with the gases themselves igniting if exposed to a flame/spark.
Stages of Wood Combustion & Gas Ignition

1. Drying (Under 500°F): Water evaporates, no flame.
2. Gassification/Pyrolysis (500-700°F): Wood breaks down, releasing flammable gases (volatiles) and tars; these gases burn if an external flame/spark is present, but don't self-ignite yet.
3. Primary Combustion (Around 540°F+): The solid wood char burns, releasing more gases.
4. Secondary Combustion (1100°F+): The key to clean burning; these high temperatures + sufficient oxygen burn the unburned gases from step 2, producing more heat and less smoke.

 

[Highbeam]

Maybe we are getting twisted on the words "thermostatically controlled".

I think when WS says "The secondary combustion system engages as exhaust temperatures reach about 1000 degrees F" they are referring to the ignition temperature when the gases naturally ignite. This would agree closely with my experience, when the stovetop reaches 500ºF the firebox ignites and the rule of thumb per WS is the stovetop is about half the internal firebox temp.

AI Overview
Wood smoke gases ignite at varying temperatures, but generally, the flammable gases (like methane, methanol) released during wood's gassification (around 500-700°F) need sufficient oxygen and temperatures of at least 1100°F (600°C) in the firebox for clean, complete combustion (secondary combustion) to burn those gases efficiently, though the initial wood ignition starts lower, around 400-600°F, with the gases themselves igniting if exposed to a flame/spark.
Stages of Wood Combustion & Gas Ignition

1. Drying (Under 500°F): Water evaporates, no flame.
2. Gassification/Pyrolysis (500-700°F): Wood breaks down, releasing flammable gases (volatiles) and tars; these gases burn if an external flame/spark is present, but don't self-ignite yet.
3. Primary Combustion (Around 540°F+): The solid wood char burns, releasing more gases.
4. Secondary Combustion (1100°F+): The key to clean burning; these high temperatures + sufficient oxygen burn the unburned gases from step 2, producing more heat and less smoke.

Now ask your AI if Woodstock uses a bi-metallic coil.

 

[Todd]

Well I don’t know what or how the air is delivered to their hybrid stoves but when I talked with Lorin awhile back she said with the new EPA test methods they had to tweak the air because they changed the test method to where they had to test at fully closed and fully open. In the past the manufacturer decided where the low and high burn rates were set. This is one of the reasons they are behind along with the Gov shutdown and figuring out the tariffs. Even the Fireview had an adjustment to the air supply system.

 

[John Lehet]

With my brand new Progress, all the way closed is still too little air, burning two or three year old cherry and ash (very dry) in a warm 25’+ chimney. I can only do shut all the way down after much of the volatiles have burned off and it’s heading toward coaling. I guess with a small load of crib wood it might work? I’m sure I’ve got an above average chimney. The sweep said I’d have to open the door or even the ash pan to get a fire going. Nope, never do with this stove so far.
I guess that with a smaller fuel load if I went black-box the cat would handle it all shut all the way down? With my stove so far I feel like with a full load of hardwood and shut all the way down it’s too much smoke for the cat to handle without flame to eat some of the smoke, so I need to open it up a bit.

 

[John Lehet]

I guess I could try no-flame burning after it’s run for a half hour or so. My attempts to black-box have been with the cat lit, but the fire still pretty new — on my way to bed. I have shut all the way down with a more mature fire, but not yet coaling, and the flames went out. Maybe I could burn that way from that point and it would be fine.

 

[John Lehet]

Anyone with a Progress and a cat probe thermometer, can you tell who made it? The parts list calls it 10” probe. Condar does not list any probes for Woodstock stoves, and their longest is 9”. Web search is not helping so far. Woodstock when I asked Lorin and Tom brushed that question off — so maybe it is better not to use one.

 

[Todd]

Only one way to find out how your stove will run on a full load with the air completely shut. 😁 no way it will overwhelm the cat, it’s been designed to run that way.

As far as probes go if you want real accuracy look into an Auber thermocouple digital probe. They can make any length you want. I can understand why Tom and Lorin are not fond of them. The bimetallic probes lag behind and accuracy problems probably gives them numerous troubleshooting calls. Also depending on the size of the cat and where the probe is located it can give false readings where one side is red hot and the other side is relatively cooler.

 

[John Lehet]

I wrote to Auber and they very quickly got back to me. Now trying to decide if I really need it. I suppose as the cat gets older it will be more useful. Need to figure out the bolt size for the adapter (and which bolt it even is).

I tried black box burning again last night. Had a very low flame under and sometimes wisping up from the logs, some spreading flames but no explosions or puffing. It would have been good, but the room filled with a creosote smoke smell. I opened it up to get some flames. I can’t complain about the overnight burn. Woke up to 66 upstairs (where we would keep the mini split) and 70 downstairs (5 degrees over what the mini split down here would do). Both mini splits off. Stove full of coals. Absolutely perfect.

I find cherry is good wood to keep the secondaries from going crazy. Less volatiles. Now I have a nice low lazy fire with mostly cherry and a bit of ash.

 

[Dieselhead]

I wrote to Auber and they very quickly got back to me. Now trying to decide if I really need it. I suppose as the cat gets older it will be more useful. Need to figure out the bolt size for the adapter (and which bolt it even is).

I tried black box burning again last night. Had a very low flame under and sometimes wisping up from the logs, some spreading flames but no explosions or puffing. It would have been good, but the room filled with a creosote smoke smell. I opened it up to get some flames. I can’t complain about the overnight burn. Woke up to 66 upstairs (where we would keep the mini split) and 70 downstairs (5 degrees over what the mini split down here would do). Both mini splits off. Stove full of coals. Absolutely perfect.

I find cherry is good wood to keep the secondaries from going crazy. Less volatiles. Now I have a nice low lazy fire with mostly cherry and a bit of ash.

How long did you char your new load? Often if you turn down too soon the sweet bbq smell will arise in the stove I run. I know it’s not apples to apples but worth a shot. Try to bake it in good and see if you are no longer dealing with it. I find It’s always more pronounced on poor draft days (warmer, foggy, rainy, etc…)

 

[John Lehet]

I turned the draft down almost right away. Had a good bed of coals, put 21 pounds of wood in with two of the bigger splits I had around. Ran it hot for about 5 minutes with the bypass open, shut the bypass with the damper at half for a short while, then all the way down. I guess too soon. Was about 20 out I think, so the chimney should have been pulling fine. Stovetop temp got up to about 500 with the black box/wispy flame. But as I say, it worked out perfectly with the flames going instead of black box.

 

[Dieselhead]

I’m not sure with the break in procedure on your stove but if you’re past that I’d run it close to wide open with bypass shut for 20-30 min, get a good char on the new load and try going low ‘n slow again. Can’t hurt to try.

 

[John Lehet]

Oh, it’s broken in fine I think, been running it 24/7 for a week. Haven’t had the stove top much over 450 though. I’ve never run it wide open damper I don’t think, have been generally trying to keep it low key between the chimney and smallish room. But today is cold and getting colder. The wind is pretty serious today, and we’ll get 0F tonight, so I think it will get a workout, and I will try letting it rip.

 

[Dieselhead]

Oh, it’s broken in fine I think, been running it 24/7 for a week. Haven’t had the stove top much over 450 though. I’ve never run it wide open damper I don’t think, have been generally trying to keep it low key between the chimney and smallish room. But today is cold and getting colder. The wind is pretty serious today, and we’ll get 0F tonight, so I think it will get a workout, and I will try letting it rip.

It will be interesting to see if it helps with the new stove👍🏼

 

[John Lehet]

I’m just going to have to get to know this stove I guess, and maybe engage Woodstock, though I’d rather not bother them if there’s really nothing wrong. It took me really a pretty long time to get to know my old Jotul — or at least the Jotul/chimney/temperature relationship. This stove is in some ways simpler but also a lot more complicated than the Jotul. Overall it’s going well and the best stove I’ve ever had, burning wood most years since 1978.

 

[begreen]

It sounds like you're doing fine John. This is a hybrid stove, and soapstone at that. It will not operate exactly like a pure cat, steel stove. Follow the manual's guidance for operation.

Never build a roaring fire in a cold stove. It takes at least 30 minutes to heat the soapstone panels of the Progress.

Attempts to reach high temperatures very quickly could result in damage to the cast iron or soapstone parts.

 

[John Lehet]

I’m certainly not going to do either of those, though I suppose I could be tempted if I were away on vacation. The manual says for a low and slow burn to set the damper to “generally about the first big notch” for low and overnight burning. Not closing it all the way. The first notch, their low and slow, gives me really active secondaries and quite a hot fire in cold weather. I nudge it between there and fully closed for overnight or for after the house is warmed up.

 

[Dieselhead]

It sounds like you're doing fine John. This is a hybrid stove, and soapstone at that. It will not operate exactly like a pure cat, steel stove. Follow the manual's guidance for operation.

Never build a roaring fire in a cold stove. It takes at least 30 minutes to heat the soapstone panels of the Progress.

Attempts to reach high temperatures very quickly could result in damage to the cast iron or soapstone parts.

If he is doing a warm/hot reload can he run the stove higher to char a load without the stove breaking? Can a soapstone stove be run hard in cold environments or are they really that fragile?

 

[begreen]

Soapstone has a lower recommended stove top high temp than steel or cast iron. Hearthstone says about 650º IIRC. It also doesn't appreciate thermal shock.

 

[Todd]

Soapstone can take the heat easily, it’s the cast iron parts that start to degrade at 1400+ degrees. Once they start to warp it can put stress on the stone and possibly crack. Soapstone masonry heaters have internal temps as high as 2000 degrees.

 

[begreen]

True that the interiors of Tulikivis get hot. Yet Hearthstone warns to not put icy splits in the stove to avoid thermal shock and states to not have the stove top over 600ºF for a sustained burn.

 

[Highbeam]

Only one way to find out how your stove will run on a full load with the air completely shut. 😁 no way it will overwhelm the cat, it’s been designed to run that way.

As far as probes go if you want real accuracy look into an Auber thermocouple digital probe. They can make any length you want. I can understand why Tom and Lorin are not fond of them. The bimetallic probes lag behind and accuracy problems probably gives them numerous troubleshooting calls. Also depending on the size of the cat and where the probe is located it can give false readings where one side is red hot and the other side is relatively cooler.

I think I see where Woodstock is coming from. If my cat meter was stolen by a stove bandit, I would have no problems running the BK by flue temperatures alone. If flue temps are above 500 then we know that sending that smoke through the cat should be at least 500 as well.

 

[Highbeam]

True that the interiors of Tulikivis get hot. Yet Hearthstone warns to not put icy splits in the stove to avoid thermal shock and states to not have the stove top over 600ºF for a sustained burn.

View attachment 344612

My old hearthstone heritage, last of the pre cat models, had 550 max in the manual.

 

[Dieselhead]

Soapstone has a lower recommended stove top high temp than steel or cast iron. Hearthstone says about 650º IIRC. It also doesn't appreciate thermal shock.

Ah ok gotcha.

 

[John Lehet]

The old Heritage had a lot of sort of mortar or cement under and between the stones? I imagine that changes the equation.

When I built my Tulikivi, I used soapstone dust with waterglass for mortar/grout, so it would expand with the stone. I built really hot fires in that firebox, Poplar with full air. After 10 years or whatever the firebox stones did show some spalling on the interior of the firebox, but they got hit with heat like you’d never see in a woodstove firebox.

 

[begreen]

Yes, each application and stove design is different. Hearthstone is single-walled stone but I think Woodstock has a double-wall design. Bottom line, go with what the stove manufacturer recommends.