BK Ashford: the limits on leaving the cat open (by mistake)

[green pacific]

I wonder whether someone can reassure me about inadvertently leaving the cat open after the needle gets into the active range on my Blaze King Ashford 30. The anxiety is dampening my pleasure in my still fairly new beautiful and congenial stove.

Could someone reassure me -- or lecture me?, or give me an ultimatum? ;-)

I have twice in the life of the young stove inadvertently left the cat open with the needle well into the active zone. Once, long ago, when the stove was new, I noticed only after an hour or more that the needle was at noon and who knew how long it'd been there.

And then this evening it happened again. Aaargh! .... happily cooking dinner, I suddenly remembered that I had left the cat open after stoking the fire because the needle had sagged into the inactive zone. It just recently got cold here so I am not dancing to the rhythms of the stove quite yet.

What exactly do I risk wrecking if I do this from time to time, as seems inevitable, sadly? And how much un-cat'd heat can the stove take before calamity strikes? (I remember someone saying he'd done the same, leaving it for a couple of hours, I think; and he reported taking the whole stove apart looking for warping; that's a clue I guess ... sigh; can I tell whether there's a reason for concern without disassembling it?)

Many thanks to anyone who knows the answer!

 

[Poindexter]

When the needle sags to inactive and you stoke.... fill er up.

It is a good time to hang out by the stove waiting to re-engage the combustor. Them set a timer for 30 minutes to come back and throttle down.


If you had the loading door latched shut for these two indiscretions yourstove is probably fine.

 

[webby3650]

Your are overreacting I’d say. A few times isn’t gonna hurt these things. I’m afraid people have gotten the impression that BKs are fragile, simply because running with the bypass open or the door ajar is the only way to hurt them. While that’s true, that doesn’t mean they are fragile. It’s certainly not a habit you’d want to get into, but a few times ain’t gonna hurt it. Now, if you have a 30’ flue, and it was filled with pine, that could be a different story I guess...

 

[RandyBoBandy]

Like poindexter said. Set an alarm if you can't hang out in the stove room on reloads. I am sure everyone on this forum could admit to forgetting about the stove on reloads or cold starts. It's definitely not a good habit to form however

 

[edyit]

I wonder whether someone can reassure me about inadvertently leaving the cat open after the needle gets into the active range on my Blaze King Ashford 30.

do you mean leaving the bypass wide open, or leaving the thermostatic control for the cat wide open?

 

[Ashful]

Your are overreacting I’d say. A few times isn’t gonna hurt these things. I’m afraid people have gotten the impression that BKs are fragile, simply because running with the bypass open or the door ajar is the only way to hurt them. While that’s true, that doesn’t mean they are fragile. It’s certainly not a habit you’d want to get into, but a few times ain’t gonna hurt it. Now, if you have a 30’ flue, and it was filled with pine, that could be a different story I guess...

Last night, I filled one of mine with hickory, and accidentally left it at wide open throttle with bypass open for maybe an hour and twenty minutes. I was on the other side of the house, so I couldn’t hear the wrinkling of the liner and the pinging if the stove, or smell the smoking paint. Eventually, I wandered back, and found that side of the house filled with smoke from the baking paint. Second time I’ve done that, in 20 cords burned over three years.

Last time, there was no damage, and I suspect this time will be fine as well. Only thing I’ll be checking is the bypass gasket retainers. If they’re good, I’m sure the rest of the stove is, too.

 

[Woody Stover]

do you mean leaving the bypass wide open, or leaving the thermostatic control for the cat wide open?

Yeah, bypass open isn't going to hurt it, just waste wood and gunk up your chimney eventually. If the thermostat isn't wide open, stove temp shouldn't be excessive. Even wide open, the thermo might shut the air down if the stove got real hot, I don't know..

 

[Highbeam]

Only thing I’ll be checking is the bypass gasket retainers. If they’re good, I’m sure the rest of the stove is, too.

This is the correct answer. Yes, you can damage your stove if you leave the bypass open too long. The BK seems a bit unique with this weakness. Those gasket retainers are the first and maybe only thing to go but replacing them is a severe punishment. Some newer models made these gasket retainers replaceable without cutting and overhead welding. Good move by BK.

So if you ever have an incident of forgetfulness where you think you bypassed for too long simply test the seal of the bypass with a dollar bill. Just like the loading door gasket. If it still seals all around then you're just fine.

I don't think it is out of line to get slightly past the active line, like 1/4" or so before engaging the cat to make sure that light off temperatures have been attained but remember that there is a lag on the cat probe and that the indicated temperature is what was actually happening severeal minutes prior.

Oh and forgetting about a raging fire happens to all of us. It can damage non-cats and other stoves as well. The good news is that once you engage the cat of a BK and shut the door you can forget about the air setting and the worst thing that happens is that your house gets hot! Folks set timers, stay to watch, this is just one of those responsibility things. You must run the stove as directed if you want a safe experience without damaging the stove.

 

[Woody Stover]

Yes, you can damage your stove if you leave the bypass open too long. The BK seems a bit unique with this weakness. Those gasket retainers are the first and maybe only thing to go but replacing them is a severe punishment. Some newer models made these gasket retainers replaceable without cutting and overhead welding

Oh yeah, I forgot about those retainers..

 

[Ashful]

The good news is that once you engage the cat of a BK and shut the door you can forget about the air setting and the worst thing that happens is that your house gets hot!.

Exactly. As soon as I closed the damper, the fire was under control. Five minutes later, I turned down the air and was in black box radiator mode. Very little excitement, bringing down from on high, compared to my prior stoves.

 

[kennyp2339]

Funny that I read this because I forgot to close my by-pass last night, it was in the open position for about 2 hours, thankfully the t-stat setting was at 2 o'clock so I wasn't really to worried, actually the fire in the fire box was rather nice, good whisper flames and the cat prob was at 10 o'clock, also no paint / burning metal smell was noticed.

 

[Highbeam]

Don't you folks all heat up the stove to the active line at full throttle? And then leave it at full throttle for the next 20-30 minutes to get the cat hot and fuel dry before turning it down? I thought the manual specified full throttle during warm up to get the cat active and engaged ASAP.

I have noticed that if I let the stove get hot by doing the 20-30 minute full throttle burn in of a new load after cat engagement that the firebox gets much hotter than my normal setting. Then when I turn it down to my normal setting the thermostat clicks shut and the stove spends so much time with a closed stat that it almost snuffs the cat before the stat reopens. This could be due to a worn out catalyst but I have found cleaner and better burns by not spending 20-30 minutes baking the fuel at full throttle.

 

[webby3650]

Don't you folks all heat up the stove to the active line at full throttle? And then leave it at full throttle for the next 20-30 minutes to get the cat hot and fuel dry before turning it down? I thought the manual specified full throttle during warm up to get the cat active and engaged ASAP.

I have noticed that if I let the stove get hot by doing the 20-30 minute full throttle burn in of a new load after cat engagement that the firebox gets much hotter than my normal setting. Then when I turn it down to my normal setting the thermostat clicks shut and the stove spends so much time with a closed stat that it almost snuffs the cat before the stat reopens. This could be due to a worn out catalyst but I have found cleaner and better burns by not spending 20-30 minutes baking the fuel at full throttle.

That’s my routine as well. Or it used to be. In my new house I’ve not been able to run it any lower than 3/4 throttle! I’ve got some work to do.

 

[Highbeam]

That’s my routine as well. Or it used to be. In my new house I’ve not been able to run it any lower than 3/4 throttle! I’ve got some work to do.

So you're not doing the superheat of a fresh load either? With wet wood sure but I want to get to that steady state with clean burn ASAP. Trying to keep it simple.

 

[webby3650]

So you're not doing the superheat of a fresh load either? With wet wood sure but I want to get to that steady state with clean burn ASAP. Trying to keep it simple.

No, I meant that I do run it on high after every reload. Overall I think it makes a much better burn, and the glass stays cleaner.
I’ve pretty much just been leaving it on high lately though.

 

[MtnBURN]

I have noticed that if I let the stove get hot by doing the 20-30 minute full throttle burn in of a new load after cat engagement that the firebox gets much hotter than my normal setting. Then when I turn it down to my normal setting the thermostat clicks shut and the stove spends so much time with a closed stat that it almost snuffs the cat before the stat reopens. This could be due to a worn out catalyst but I have found cleaner and better burns by not spending 20-30 minutes baking the fuel at full throttle.

What I've noticed with my stove here in the house (the one I use the most) is that if I turn down the thermostat >quickly< I hear the "click" much sooner than if I take the time and >very< slowly adjust the dial. Quickly it will shut down at 3 o clock....slowly and it doesn't click until close to 1 o clock. Does anyone else notice/experience this?

I let my stove rip til it hits active...then bypass...wait a few minutes...crank it to 3 oclock....wait til it starts to build...then drop it as low as it will go....slowly...and still not "click". My stove usually runs about halfway on the dial at these settings. Anything higher on the dial and we are opening windows and stripping off clothes. (not always a bad thing...heehee)

 

[Marshy]

I think the stoves will take more punishment than most of you realize. While i don't suggest you purposely subject the stove to unnecessary punishment, I bet the stove will be unaffected by a handful, even a dozen of "oops I left the bypass open". Just a hunch, nothing conclusive or factual to support that.

If you think that's bad, leave the loading for cracked and bypass open and thermostat wife open. That'll heat things up and cure paint you didn't know could.

 

[SuperJ]

What I've noticed with my stove here in the house (the one I use the most) is that if I turn down the thermostat >quickly< I hear the "click" much sooner than if I take the time and >very< slowly adjust the dial. Quickly it will shut down at 3 o clock....slowly and it doesn't click until close to 1 o clock. Does anyone else notice/experience this?

I let my stove rip til it hits active...then bypass...wait a few minutes...crank it to 3 oclock....wait til it starts to build...then drop it as low as it will go....slowly...and still not "click". My stove usually runs about halfway on the dial at these settings. Anything higher on the dial and we are opening windows and stripping off clothes. (not always a bad thing...heehee)

That makes sense, the thermostat will be biased closed if run on high for a while, but will thermostatically open a bit each time you turn it down. I like to set mine past the closed click when turned it down, but not so far that it can't open once it's in the cooling of coaling phase. You know you turned it down too far if the cat goes inactive with significant chunks left. In order for me to get full consumption I have to have the stat around 3 oclock. This means it's thermostatically fully closed for the majority of the burn but has room to open substantially at the end of the burn cycle as things start to simmer down. If I happen to catch the stove at the end of the coaling phase but with a still active cat I'll rack the coals together and forward and max out the stat for another couple hours of heat, or I'll reload at the point if it's the evening.

For me there is no point turning my stat closed past 1 oclock since it will never open at all, and will probably go inactive before everything is consumed. The real range is between 3oclock and 5 oclock for me.

I'm not sure what to do with the bypass if the cat has dropped into the inactive range. By the coaling stage it seems there isn't near the creosote production so I'm wondering if it's okay just the leave the bypass closed.

1. just crank the thermostat up and leave the bypass closed. And hope that it goes active again
2. crank the thermostat, open the bypass until the temp shows active, and then close it
3. open it and leave it open for the rest of the coaling cycle (assuming I'm not reloading).

 

[Highbeam]

That makes sense, the thermostat will be biased closed if run on high for a while, but will thermostatically open a bit each time you turn it down. I like to set mine past the closed click when turned it down, but not so far that it can't open once it's in the cooling of coaling phase.

The thermostat will not open a bit each time you turn it down. It will open a bit as the stove cools. Some installations allow extended periods with the thermostat totally shut but some will stall the cat so the amount of time with the stat shut becomes important. This amount of time is determined by how hot the stove was before turning down the stat and how low you turned the stat. It can be a polluting mess for some. Weak/old cats make this much worse.

I'm not sure what to do with the bypass if the cat has dropped into the inactive range. By the coaling stage it seems there isn't near the creosote production so I'm wondering if it's okay just the leave the bypass closed.

Don't overthink it. If the fuel has dwindled to the point that there is insufficient fuel to keep the cat active then just leave it be until you are ready to reload.

 

[SuperJ]

The thermostat will not open a bit each time you turn it down. It will open a bit as the stove cools. Some installations allow extended periods with the thermostat totally shut but some will stall the cat so the amount of time with the stat shut becomes important. This amount of time is determined by how hot the stove was before turning down the stat and how low you turned the stat. It can be a polluting mess for some. Weak/old cats make this much worse..

I think I should clarify, that the thermostatic throttling well be reduced when you close it a bit unless it was so hot that it had pinned is response to max closed.

actual air intake position = manual knob setting (0-100%) + the thermostatic response (0 to neg 80%ish)

So if the manual setting is 100% open. Then the actual air intake position could be anywhere from 100% to 20% open depending on how hot the thermostat is. If you lower the manual adjustment, then the heat will go down and the thermostatic reduction will decrease (meaning you can turn the manual setting lower without fully closing the air intake when the stove is less hot).

 

[SuperJ]

Duh, I just realized tonight that I hadn't been closing the bypass properly up until now. I flipped the lever over to the point where the handle pointed backwards horizontally. I was trying to figure out the cam over feeling that was supposed to be there and realized I could push the handle down another 30degrees or so adding some tension to the bypass closure.
So up until now it's basically just been gravity holding my bypass shut not any tension from the rod. I still seemed to get long 24hr+ active cat times so I'm not too concerned, but I did noticed the flames projecting more forward on high with the tension increased on the bypass (by fully stroking the handle).

 

[green pacific]

Thanks everyone for your advice and experiences. I feel better now.... Definitely haven't left the loading door open, just the bypass.

I'm especially glad of the advice to dollar-bill-test the gasket for the bypass and because it's so warm here at the moment (nearly midnight and it's still over 40F on south Vancouver Island), it's the perfect time to try that.

And thanks, SuperJ, for asking my next question -- what to do when the thermometer drops into the inactive range while I'm asleep because I've edged the thermostat just a little too low (at these mild temperatures, even 3 o'clock is a bit risky). Good to know it's ok.

 

[green pacific]

I tried the dollar-bill-test on the bypass and find that it is fairly tight all around except along the back edge (edge facing back of stove) where I can easily slide the bill from one end to the other. In fact, SuperJ, it's better when I don't push the handle down the last 25 degrees; that last push seems to pull the edge up just enough so there's no seal. Without that last push, it sits down better ...

Ok, you merry band of experts ... now what? I think I dimly remember something in the manual about this but I would much prefer to hear from folk here who've lived with these stoves.

 

[Highbeam]

You can tighten the bypass. It's not unlike tightening the door latch to make the bypass door clamp down harder. Instructions should be in your manual.

This bypass seal is important but not as critical as the loading door. The bypass gasket is replaceable but it should have a long life like 10 years!