Seeking advice on new stove BK Soricco vs HT3000

[Moose032]

It's actually been this way all along. But for bragging rights in marketing, stove marketers went with the full firebox volume, including above the baffle, instead of the actual usable volume. If your competitors were doing this, then you needed to do the same.

Now, with the new regs, the EPA testing labs started reporting the actual usable firebox dimensions because this was part of their calculations. With this number now exposed in the testing docs, manufacturers started reporting the actual usable size of the firebox. It's a dramatic difference in some cases. For example:

View attachment 349115

This is the best explanation of this I’ve seen. I remember these differences could be somewhat confusing/misleading when I was looking at new stoves.

 

[begreen]

About 15 yrs ago I had a discussion with an SBI rep about this. Users were measuring their fireboxes and the numbers didn't jibe with the marketing numbers.

 

[Steveb123321]

OMG!
Just priced oem cat for the “princess 32” $980 CDN before tax!
I know it has a 10 year warranty for the first one. I just saw someone’s post saying they change their cat every 3 years. If this is the case I’ll try to cancel my stove order!

Edit: found midwest aftermarket on amazon for $500 CDN.

 

[stoveliker]

That is ridiculous indeed. If that remains, BK will go out of business

 

[Steveb123321]

That is ridiculous indeed. If that remains, BK will go out of business

Yes I think it is crazy. I was expecting a few hundred every 10 years. I hope I only have to pay $500 every 6 or so years

 

[stoveliker]

Midwest hearth sells them for $319 at the moment.
Steel cat, not ceramic (but despite some folks badmouthing the steel ones I have no issues with them.)

 

[Steveb123321]

Midwest hearth sells them for $319 at the moment.
Steel cat, not ceramic (but despite some folks badmouthing the steel ones I have no issues with them.)

How often are you having to replace the cat?

 

[stoveliker]

I got my stove in 2020. Still the original cat, but this may be the last season.
So no real data here.

But this depends a lot (I believe) on burning habits.
High or low, how fast do you close the bypass, how long is the bypass open before you open the door, how high is your draft, what wood are you burning.
Etc

And some say a cat is not expected to last more than 12000 hrs so it then Also depends on burn time per season.

 

[Dieselhead]

How often are you having to replace the cat?

I burn part time oct through mid November then typically full time until march then on and off through April and can get 4 years out of a cat but find its best to replace after year 3. Year 4 typically has more creo in the chimney so I don’t think the cat is as effective. They are rated for 12,000 hours. Midwest hearth sells the real McCoy and is a trusted source for replacement cats. The last one I bought for my big king was $319 for the ceramic which you can use if it’s available for your size stove.

 

[Todd]

Good lord these things are expensive! $6k stoves and $980 cats!😳 I can see why there is a strong market for used stoves. I noticed Woodstock doubled their prices on their cats from $160 to $320 for the Fireview! I prefer their steel cat but Midwest ceramic is much cheaper!

 

[Steveb123321]

@stoveliker - Thanks, that 12k hour number is what I had seen as well.

@Dieselhead - We burn a little more than you. I can get the Midwest hearth cats for $500 canadian on Amazon. I could drive to Maine in 3 hours as well tho .

@Todd Those are Canadian prices, but yeah nuts. I ran my last non-cat stove for 20ish years changed the baffle couple of years ago after it cracked. Still works great. I guess I’ll still save some $ on the cold mornings where my heat pump switches to aux heat coils. Also probably burn in Oct and Apr where I didn’t before. That should pay for the cats.

I ordered the stove on Thurs. Still thinking about trying to cancel.
Edit: also worried about cost and availability of cats in the future. Without the cat these stoves would be a boat anchor.

 

[stoveliker]

True all that.
The world has changed since I got my stove in '20 (right before Covid hit...).

 

[Steveb123321]

I talked to the dealer today. They assured me that I would should get 9 years life out of the cats burning a couple of cords per year. She sent me an email with this doc.

She was nice and she believes what she was told.
I’m more inclined to believe the real world experience I have read on this forum.

I attached what she sent. I noticed the qualifying words ‘up to 3 cords’ in the doc.

 

[stoveliker]

Yeah, I don't buy that.
It's *not* common to have a working cat for 12 years, as they state in the second part. Not here, at least.
Maybe some folks leave the cat in for that long - but maybe they should have replaced it much sooner.

I burn 2 cords a year. I started spring 2020 with only a few burns, so first full winter was '20-'21. So upcoming winter will be my 7th with this original cat.
I think its efficiency is decreasing, so I'm going to keep an attentive watch to my chimney exhaust, and to the temperature behavior. We'll see.

I know BKVP mentions these timeframes, but I just have not seen folks here with that experience. And I note that BK folks are notoriously (justifiably ) braggadocious about their stove performance, so folks running that long would likely have jumped in and told all of us about it.

Maybe there really a few. But the majority here won't reach that.

Nevertheless, 4 years or so is fine, with me, for the performance it provides.
Though not for $1000 per 4 years...

 

[Steveb123321]

I’ll be fine with $500 canadian ever 4 years.

 

[begreen]

If making a trip to Maine, maybe invest in a couple of spare cats?

 

[Steveb123321]

I asked gemini (google AI) to find read and summarize studies found online. Make a report for cat stoves efficiency as the precious metals degrade. I make no claims how accurate it is.

I am curious if lived experience with cat stoves is close? Opinions welcome please.

I had it create a disclaimer as well.
Disclaimer: This document is provided for informational and educational purposes only. While every effort has been made to synthesize research accurately, the contents should not be taken as technical, professional, or WETT/safety advice. Wood stove installation, operation, and clearance requirements vary by model, local building codes, and manufacturer instructions. Always consult certified hearth professionals, local authorities, and your specific appliance manual before making installation or operational decisions. The author assumes no liability for errors, omissions, or any actions taken based on this post.

 

[Turbo89]

That’s an interesting report, i wonder if it’s specific to ceramic or steel cats? I’ve noticed my VCs CAT has gotten a little harder to light off as it’s aged, but haven’t noticed and reduction in burn time.

 

[Steveb123321]

I don’t want anyone to think I believe everything AI tells me but this is what it said.

The studies specify that early EPA field research (like the OMNI studies) evaluated cordierite ceramic honeycombs, which were prone to structural cracking and crumbling from thermal shock before their catalytic coating wore out. Modern comparative research includes metallic stainless steel substrates, which heat up much faster and eliminate physical cracking, though their tighter cell structures require regular vacuuming to prevent fly-ash clogging.


Regardless of whether the substrate is ceramic or steel, the chemical degradation rate is identical because both rely on the same platinum/palladium noble-metal washcoat. For a high-use 4,000-hour annual burn schedule, stainless steel combustors offer superior physical durability, while ceramic models provide slightly better resistance to ash buildup—but both will follow the same 12,000-hour chemical lifespan curve.

 

[begreen]

The degradation is similar to efficiency decline in ICE vehicles between parts replacement and tuneups. Another early (1998?) report showed that poor user maintenance of all the stoves tracked led to degraded performance over time. For some of the stoves, the degradation was significant.

This is from a 2012? OMNI lab report:

"In general, the field studies showed that emissions from both non-catalytic and catalytic heaters increased with use and that some heaters showed physical deterioration. The level of deterioration appeared to be related to how “hard” the heaters were used. Those that were burned at high burning rates with high draft chimney conditions showed the most wear. Some models appeared to have less deterioration than others. Catalytic heaters were more susceptible to deterioration than non-catalytic stoves due to damage to the catalyst itself and the catalyst bypass which is a sealing/moving part. Damage to non-catalytic heaters was primarily to the baffle/secondary air system"

https://cdn.prod.website-files.com/...rs-for-Certified-Residential-Wood-Heaters.pdf

 

[stoveliker]

I think relating the cat efficacy to burn time is flawed.

Burn time is set by how much air/oxygen is provided to the fuel. That determines how fast the load burns, AND what unburnt products (smoke) is produced. I.e. a low air setting creates a long-"burning" smoldering fire with lots of unburned gases and particulates.
The cat dying does not influence the burn time, it merely influences how well it cleans up the exhaust coming out of the stove and into the chimney.

Now for a thermostatically controlled stove there the temperature (or heat output) is measured downstream from the cat and not too far from the cat, there what the cat does (i.e. how "alive" it is) will have an influence as it affects the temperature of the exhaust on the backside of the cat. I.e. if the cat is alive and kicking (e.g. glowing) with a smoldering smoky fire, the exhaust will be hotter than if you would have a dead cat with the same smoldering fire. As a result, the thermostat will decrease the air setting in the case of an alive cat as compared to the case of a dead cat - and thus affect (lengthen) burn time for an alive cat.

But if no *control* is present that depends on the temperature after the cat, then the cat liveliness will not affect burn time imo.
(And thus the AI report is a bit off there, I suggest.)

(Unless, of course, one argues that the human controlling the stove would increase the air setting for a dead cat and thus decrease burn time - but that's human action not "stove burn time for an xx lbs load".)

 

[Steveb123321]

I think relating the cat efficacy to burn time is flawed.

Burn time is set by how much air/oxygen is provided to the fuel. That determines how fast the load burns, AND what unburnt products (smoke) is produced. I.e. a low air setting creates a long-"burning" smoldering fire with lots of unburned gases and particulates.
The cat dying does not influence the burn time, it merely influences how well it cleans up the exhaust coming out of the stove and into the chimney.

Now for a thermostatically controlled stove there the temperature (or heat output) is measured downstream from the cat and not too far from the cat, there what the cat does (i.e. how "alive" it is) will have an influence as it affects the temperature of the exhaust on the backside of the cat. I.e. if the cat is alive and kicking (e.g. glowing) with a smoldering smoky fire, the exhaust will be hotter than if you would have a dead cat with the same smoldering fire. As a result, the thermostat will decrease the air setting in the case of an alive cat as compared to the case of a dead cat - and thus affect (lengthen) burn time for an alive cat.

But if no *control* is present that depends on the temperature after the cat, then the cat liveliness will not affect burn time imo.
(And thus the AI report is a bit off there, I suggest.)

(Unless, of course, one argues that the human controlling the stove would increase the air setting for a dead cat and thus decrease burn time - but that's human action not "stove burn time for an xx lbs load".)

I agree with you, about the burn time.

I asked gemini why:
“Burn time decreases as a catalytic combustor degrades because the catalyst loses its chemical reactivity, requiring higher firebox temperatures and more air to stay active.”

So maybe only low temp burns would change?

Honestly I put more stock in peoples experience than what AI put together.

I have never run a cat stove, I have no first hand data. I’m trying to figure out what I’m in for

I only have a few years experience with a wood furnace (in a previous house) and about 23 years with my non-cat.

So far “I think” I have learned I will need to change the cat every 3-4 years (12000-14000 hours) to keep creosote levels in check and heat output good?

My wood is always less than 15% moisture content. It is already seasoned when I get it every spring. i checked earlier today 12-15%

 

[stoveliker]

You'll have to keep an eye on what comes out of the flue. Some smoke sometimes is normal (when the air adjusts b/c temperatures change, the cat is not instantaneous in being able to consume all additional smoke, as it has to heat up a bit to do so, so there'll be some smoke intermittently), but when you constantly see smoke and when you open the bypass (without changing the air settings) what comes out of the chimney does not change much, then you know your cat is completely done.
Somewhat done means observations somewhat like the above

When you decrease the air (bypass already closed, stove in steady state), the cat temperature generally goes *up* a bit in 15-30 minutes - because there's more smoke to combust . If that does not happen, that's an indication (especially if you see smoke coming out the chimney persistently).

You'll have to get the hang of how the cat behaves. Initially it'll be young and wild ("too hot"), but it'll mature and settle down after - something between 10 burns and a cord... Don't know what that depends on, possibly type of wood (and draft, and thermostat setting, and etc. etc.). Then you're cruising and get used to how it behaves.
At some point it should start changing (for the worse). That is a slow onset. So it's easy to miss it, I presume.
I think I'm (nearly?) there now. We'll see this season.

Others here have gone through many more cats.
But observations do differ quite a lot burning sappy wood (e.g. pine), like @Highbeam or red oak. I've burned quite some pitch pine (very sappy, used to seal wooden whaling ships in the 1800s here), and a lot of oak. It's different.
So each observation/experience you hear about will be useful, but may not be what you're seeing. Your system and fuel, and running demands will be different than others.

Just pay attention when you burn - as much as possible so you learn, get a feel for how the thing behaves.

 

[steadyheath]

You'll have to keep an eye on what comes out of the flue. Some smoke sometimes is normal (when the air adjusts b/c temperatures change, the cat is not instantaneous in being able to consume all additional smoke, as it has to heat up a bit to do so, so there'll be some smoke intermittently), but when you constantly see smoke and when you open the bypass (without changing the air settings) what comes out of the chimney does not change much, then you know your cat is completely done.
Somewhat done means observations somewhat like the above

When you decrease the air (bypass already closed, stove in steady state), the cat temperature generally goes *up* a bit in 15-30 minutes - because there's more smoke to combust . If that does not happen, that's an indication (especially if you see smoke coming out the chimney persistently).

You'll have to get the hang of how the cat behaves. Initially it'll be young and wild ("too hot"), but it'll mature and settle down after - something between 10 burns and a cord... Don't know what that depends on, possibly type of wood (and draft, and thermostat setting, and etc. etc.). Then you're cruising and get used to how it behaves.
At some point it should start changing (for the worse). That is a slow onset. So it's easy to miss it, I presume.
I think I'm (nearly?) there now. We'll see this season.

Others here have gone through many more cats.
But observations do differ quite a lot burning sappy wood (e.g. pine), like @Highbeam or red oak. I've burned quite some pitch pine (very sappy, used to seal wooden whaling ships in the 1800s here), and a lot of oak. It's different.
So each observation/experience you hear about will be useful, but may not be what you're seeing. Your system and fuel, and running demands will be different than others.

Just pay attention when you burn - as much as possible so you learn, get a feel for how the thing behaves.

The slow decline is the part that'd bug me, since it can sneak up while the stove still seems to be doing its job. Watching the flue and cat temp over a season sounds more useful than chasing a fixed replacement schedule.

 

[Steveb123321]

The slow decline is the part that'd bug me, since it can sneak up while the stove still seems to be doing its job. Watching the flue and cat temp over a season sounds more useful than chasing a fixed replacement schedule.

How often do you find you need to replace your cat?