Running with the bypass open

[Hoytman]

Mod Edit: Extracted from the BK40 smoke smell thread. It branched off into a separate topic.

Wonder if it would help to burn it with the bypass open for awhile?

In my mind there’s no need to use the catalyst while curing paint. That allows the user to control the burn with the amount of fuel going from small to larger with each consecutive burn. Heat stove up to 300 let it burn out. Then 400 let it burn out. Four fifty, and so on. This allows the stove and the pipe to get hotter. BK exhaust is generally cooler compared to other stoves, so an open bypass allows the stove pipe to cure at a much hotter temperature to burn off oils and paint.

Unless I’m missing something with regard to how a BK runs, you should be able to leave the bypass open and the bi-metal thermostat should still control heat output of the stove. That’s my understanding of how they work, but I could be wrong.

Once the oils and paint of both stove and pipe have burned off and cured, then close the bypass to engage catalyst and set the dial to desired temperature to run as normal.

I’ll bet there’s a section on new stove break-in and paint curing in the manual that comes with the stove. It’s always easy to miss things in writing. Pays to read the manual more than a few times.

Good luck.

 

[Ashful]

On most cat stoves, running with the bypass open can damage the bypass damper or frame. The bypass on most stoves is a 30 - 40 sq.in. hole in the firebox, which goes straight up the pipe, and leaving it open can make the stove difficult to control on a full load.

If done with small loads, I suppose it could be made to work, but I don't think it's advised. I'm also not convinced anymore that what this user is smelling is indeed paint. May be something else.

 

[Hoytman]

I wasn’t suggesting full loads, rather break-in loads successively larger to just reach a new and increasing degree of temperature in order to do a proper break-in of the stove/steel and to burn off paint.

There should be no damage to any bypass or bypass frame because the thermostat still controls the amount of temperature the stove is allowed to get to as well as load size limits the temperature and length of burn. If that damages those parts then they are in no way built heavy enough in that case. However, the context of my comments wasn’t extended burns, rather reach a temperature and let the stove completely cool down. Then do it again allowing stove to get a 50-100 degrees hotter with each load, let it burn out and cool again and repeated until break-in period is over.

Short burns successively hotter with cooling between. That stove should be able to handle that.

Besides, I’d say it’s built in to handle some burning when a CAT no longer works to allow a family to keep warm (warm not hot…some common sense must be used) while waiting on delivery of a new catalyst. I’m sure BK doesn’t expect someone to, “Don’t use your stove at all while waiting on a catalyst”, as that would be absurd.

You have to remember the dial (bi-metal thermostat) controls the temperature of the stove regardless of a clogged or failed catalyst. Think of how an EarthStove worked with a bi-metal thermostat with no catalyst or secondary air tubes. My stove doesn’t have those either but it has the thermostat. The thermostat keeps those stoves running the temperature you set it to regardless of a catalyst or secondary air tubes.

What they probably don’t want people doing is burning it on high for days, weeks, and months on end without a working catalyst and/or using it for long periods on high burn with the bypass open.

I’m sure short successively hotter break-in fires aren’t going to hurt the stove. As I said, I’m sure the manual has proper break-in procedures written into the manual and possibly how to use the stove and stay warm when a catalyst has failed.

Obviously, a clogged catalyst isn’t going to allow the stove to breathe so the by-pass would have to be opened.

If when waiting on a catalyst to arrive, or during some other emergency where I needed heat and BK tells me not to ise the stove at all, then I would be skeptical of build quality and especially sinking $4k-$5k into a boat anchor. I doubt the stove is a boat anchor.

 

[Highbeam]

There should be no damage to any bypass or bypass frame because the thermostat still controls the amount of temperature the stove is allowed to get to as well as load size limits the temperature and length of burn. If that damages those parts then they are in no way built heavy enough in that case.

This, unfortunately, is false. The BK bypass frame is not built heavy enough to withstand being burned with the bypass open. It can even melt these parts with the bypass closed. Always close the bypass when the cat meter indicates "active" to minimize the chance of permanent stove damage.

If you must burn without a catalyst, remove the catalyst and close the bypass so the smoke has to go through the old cat hole.

Replacing that bypass gasket frame is cutting and welding inside the stove in a very difficult place to access. I wish I could find somebody skilled enough and willing to do it.

 

[BKVP]

There have been no issues with the bypass designs that were modified 5 years ago. The bypass gasket retainer is a one piece. The very few issues were related to those with the 4-piece design years ago. They are very robust in the current design.

However, you should not burn the stove with either the bypass open or remove the combustor. Instead, isolate the cause of concern and have the dealer involved to address the concerns.

BKVP

 

[NHWS]

This, unfortunately, is false. The BK bypass frame is not built heavy enough to withstand being burned with the bypass open. It can even melt these parts with the bypass closed. Always close the bypass when the cat meter indicates "active" to minimize the chance of permanent stove damage.

If you must burn without a catalyst, remove the catalyst and close the bypass so the smoke has to go through the old cat hole.

It must be sturdy enough to handle it for a short while, though (10 minutes? 20 minutes?), since otherwise it would not be possible to do a hot reload.

 

[Hoytman]

There have been no issues with the bypass designs that were modified 5 years ago. The bypass gasket retainer is a one piece. The very few issues were related to those with the 4-piece design years ago. They are very robust in the current design.

However, you should not burn the stove with either the bypass open or remove the combustor. Instead, isolate the cause of concern and have the dealer involved to address the concerns.

BKVP

In other words don’t use the stove, @BKVP?

Glad to hear they beefed up the bypass area on newer models. That’s a plus.

I could understand Highbeams comments removing the bypass so as not to damage bypass components, but apparently you’re not even recommending that…even in the context of break-in fires?

 

[Hoytman]

There have been no issues with the bypass designs that were modified 5 years ago. The bypass gasket retainer is a one piece. The very few issues were related to those with the 4-piece design years ago. They are very robust in the current design.

However, you should not burn the stove with either the bypass open or remove the combustor. Instead, isolate the cause of concern and have the dealer involved to address the concerns.

BKVP

Hard for a dealer to address ordering a catalyst in the event there’s a supply chain glitch, like during covid, in which the BK owner is just out of luck. I guess if there’s a long wait on catalysts, like Woodstock had, I suppose the BK owner has no option but to find alternative heat?

 

[Hoytman]

So in the context of having to use the stove for longer periods after stove break-in …

Are the EPA regulations such that your stove can’t be used in an emergency even temporarily while waiting on a new catalyst?

I’m trying to wrap my head around this. Take the catalyst away from your stove and it would be hard to convince me it’s any different than an old EarthStove or Hitzer. Sure, the air is coming in from different areas, but that in itself doesn’t make the BK any more unique, not unless the youtube videos showing cut-aways of the BK stove aren’t showing all the details.

The catalyst is what makes the BK what it is, not the bi-metallic….combined they’re a hell of a team, I’ll give you that. My friends used BK King model has impressed us both, to the point I’d love to have one.

Just seems a lot to be putting the additional cost and burden of having an extra, and expensive catalyst, on hand after spending $5k on a stove plus another $2k-$5k for the proper chimney to run it, when it can’t even be used if a catalyst fails prematurely and it’s not supposed to be run with catalyst removed.

I hope I’m not sounding argumentative because that’s not my intent at all. I think it’s a legitimate concern that for any reason should a catalyst become unusable that it totally disables a $5k stove. I can’t wrap my head around that. I can’t wrap my head around the BK stove not being built heavy enough to handle running like a normal stove.

I understand…wait…no I don’t understand if EPA regulations prevent freedom of discussion to the point there are liability concerns, if that be the case…and I’m not saying it is, just thinking outloud.

 

[Hoytman]

It must be sturdy enough to handle it for a short while, though (10 minutes? 20 minutes?), since otherwise it would not be possible to do a hot reload.

If I recall correctly most manufacturers of stoves with secondary air tubes they recommend charring all of the wood and then begin turning down the air in small increments. The BK is possibly different?

I’m not sure about BK’s recommendations, but I assume since my friends BK still has uncharred wood in it even near 40 hours 😂 of burn that the hot reload the bypass can be closed again as long as catalyst temps are still within the active range. I’m sure @BKVP will confirm or deny my assessment of the hot load procedure. Perhaps they don’t recommend a hot reload for fear of thermal shock damage to the catalyst?

I am off topic, but had some concerns and questions. That’s the way forum threads go…they eventually find their way back on topic.

 

[BKVP]

In other words don’t use the stove, @BKVP?

Glad to hear they beefed up the bypass area on newer models. That’s a plus.

I could understand Highbeams comments removing the bypass so as not to damage bypass components, but apparently you’re not even recommending that…even in the context of break-in fires?

No. Please call your dealer....

 

[BKVP]

If I recall correctly most manufacturers of stoves with secondary air tubes they recommend charring all of the wood and then begin turning down the air in small increments. The BK is possibly different?

I’m not sure about BK’s recommendations, but I assume since my friends BK still has uncharred wood in it even near 40 hours 😂 of burn that the hot reload the bypass can be closed again as long as catalyst temps are still within the active range. I’m sure @BKVP will confirm or deny my assessment of the hot load procedure. Perhaps they don’t recommend a hot reload for fear of thermal shock damage to the catalyst?

I am off topic, but had some concerns and questions. That’s the way forum threads go…they eventually find their way back on topic.

Yes you can immediately close bypass anytime the cat is active....

BKVP

 

[NHWS]

Just seems a lot to be putting the additional cost and burden of having an extra, and expensive catalyst, on hand after spending $5k on a stove plus another $2k-$5k for the proper chimney to run it, when it can’t even be used if a catalyst fails prematurely and it’s not supposed to be run with catalyst removed.

Any part can be subject to manufacturing defects and can fail prematurely. Some parts, like cats, can fail early due to user mistakes. After the supply issues of the last few years, it seems like a good idea to order replacements for such parts well before they are needed.

Cats are not cheap, but compared to the fuel savings they provide, they are not expensive, either. My stove is new (a few months), but I've already ordered another cat for it. If the original fails early and it isn't my mistake, BK will replace it - with some delay. I'll be able to keep using the stove with a new cat while waiting for the BK replacement.

The biggest downside that I see to ordering my next cat now is that the limited MidWest Hearth warranty will probably run out before I actually install it.

 

[Hoytman]

Obviously keeping the xtra cats on hand is the best way to curtail such a problem. However, that may not be realistic for some people and avoids the questions and concerns I have.

Lots of stoves have replaceable parts by design. Over time they warp and need replacement. I get that. They warp over time. Over time! Not…don’t use the stove without a catalyst even if the bypass is closed and certainly not with the bypass open.

The dealer isn’t going to be able to help anyone in the middle of the night when you desperately need heat and your catalyst fails or clogs completely … apparently rendering your stove useless. Obviously, a person shouldn’t let a catalyst get in that condition, but obviously emergencies happen and when least expected. That’s the reality of life itself.

Reality is if an emergency arises and people need heat…cat failed, clogged, whatever, bypass parts warping and failing, new stove or not, their reality is they’re going to use the stove rather than let their family freeze.

Keeping an extra CAT around won’t deter me from buying one of these, as I’m otherwise thoroughly impressed with the long clean burns, but I’m not afraid to make it known that I’m not at all impressed with actually “having to keep an extra catalyst on hand”, nor the stove being rendered useless should I not have access to one.

Reality is people forget to order things too. I feel sorry for folks in really cold climates (middle of the bush in Canada or Alaska) that have this kind of reality hit them unexpectedly. Would be a tough lesson.

 

[Ashful]

If when waiting on a catalyst to arrive, or during some other emergency where I needed heat and BK tells me not to ise the stove at all, then I would be skeptical of build quality and especially sinking $4k-$5k into a boat anchor. I doubt the stove is a boat anchor.

I'm having trouble even imagining a scenario where I own a cat stove, and have no combustor to stick in it. Are you presuming someone breaks into my house, open the stoves, steals the combustor out of it, and leaves everything else operational?

If you own a cat stove, stick a damn combustor in the hole, close the bypass, and burn it as instructed. It's not that difficult, no need to re-figure your own way around the recommended operating procedure. If your combustor is compromised, don't presume you're going to be somehow better off flying commando, just leave the bad combustor in the stove and burn on it until the new one arrives.

 

[Ashful]

I’m not afraid to make it known that I’m not at all impressed with actually “having to keep an extra catalyst on hand”, nor the stove being rendered useless should I not have access to one.

I think you'd be better off with a non-cat. As has been said by many on this forum, cat stoves aren't for everyone.

Of course, I’m not sure how well any of them will work with key components somehow missing, either.

 

[Highbeam]

Maybe the concern is that the catalyst is plugged solid with ash and can’t be cleared. I don’t think this can happen.

Reading between the lines it appears better to run a bk with a dead cat installed than to remove the dead cat and run catless. Both are better than running with an open bypass.

When cats expire, in my experience they stop working at the bottom end when you’re trying to run the stove low. Running higher stat settings you can get by with a pretty dead cat.

If you’re unwilling to be dependent on sourcing replacement cats then consider a noncat. No cats needed. You pay for that with shorter burn times, lower efficiency, etc. but everybody has priorities.

 

[Hoytman]

I already stated the best way to avoid this situation is to have parts on hand, factory parts or parts sourced elsewhere. Duh!

The proper context of my comments was in regard to short hot break-in fires (like curing the paint), and using the stove in an emergency with some common sense. An example of using the stove in an emergency would be:

A person living in a remote area needing the heat from their stove and having a need to clean the catalyst (vinegar bath for instance) and realizing you destroyed the gasketing or possibly even dropped a ceramic catalyst and broke it into pieces. Things happen. Does no good to replace a badly broken ceramic catalyst with half a missing gasket. No need to act like people can’t/don’t forget to order extra parts to keep on hand, or that things can’t happen in the supply chain to delay delivery. It wouldn’t make sense suggesting that after witnessing what politicians allowed covid to do to the supply chain recently.

You folks in Philly have to worry about people breaking into your home and stealing your cat. LOL! Of course, living in a highly populated area would explain why a person couldn’t think of such scenarios as mentioned above…because location ensures quick delivery of a new catalyst. By the way, no one is trying to avoid proper operation instructions.

No one was saying burn the stove on high heat for long periods of time, whether in context of breaking in a stove or emergency use over a longer period. How the heck can the parts even survive the first 20-45 minutes of trying to get the cat probe into the proper operating temperature…with the bypass open, if the parts will warp so easily? That alone convinces me the parts will be just fine under a lower burn. Seems more like someone redirecting to talk to dealers rather than say in public how to proceed for fear of liability issues. Reality is things happen unexpectedly and at the worst times.

Catalyst not functioning and still in place, and/or removed, bypass open or closed, apparently we’re being told that the thermostat can’t run the stove on low without doing damage to bypass and frame and/or other components. If that’s the case on a low burn, even with parts that have been beefed up, then I find that stove lacking in integrity. Low burn even…wow.

I’m in no way bashing a product that I’ve been interested in buying used for over a year. I’m just saying those comments “don’t burn the stove” and “contact your dealer” raised red flags with me.

By the way, I’m impressed with the clean burn and burn times of these BK stoves. That’s why I want to try one, and I will hopefully soon.

A forum member local to me, @logfarmer, has been sharing information with me on his BK purchase for quite awhile now and we’re both highly impressed, so some of you would be way off base trying to paint me as a BK hater because I raise some questions and have some concerns. Nothing could be further from the truth.

I guess the bottom line is if BKVP says not to run them that way, even temporarily with some common sense, then you don’t run them that way.

For some of you recommending a tube stove…I’m already ahead of you. I have them already. Just sold one and have one left.