Please define "stalled cat"

[Poindexter]

What does it mean, "the catalytic converter stalled"?

Don't want to misuse the term.

Thanks.

 

[weatherguy]

Temp isn't high enough to burn the smoke as it passes through

 

[Woody Stover]

Or wood not gassing enough for a robust cat burn, cat temp then drops and cat quits. Or the wood is too wet.

 

[tarzan]

Interesting post! I assume (with the BK anyway) that it would mean cat thermometer got to active zone. You closed bypass door. Cat thermometer came back out of active zone.

Of course this would also assume you had sufficient wood in the stove for cat to be active but I havn't had it happen yet.

 

[mellow]

A good way to stall a cat is opening the door mid burn and throwing in more wood then closing it back down, especially with wet wood.

You can watch the temps on the cat probe drop and smoke will start coming out of the chimney every time.

 

[Quentin2]

When I've stalled a cat, it's usually been from getting too greedy with turning the stat down a little too far. I had a good fire with cat active turned it down too much, come back hours later to find cat inactive and a bunch of unburnt wood. Only done it a couple times.

 

[begreen]

This is what I think of when I hear stalled cat:

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[rdust]

When I've stalled a cat, it's usually been from getting too greedy with turning the stat down a little too far. I had a good fire with cat active turned it down too much, come back hours later to find cat inactive and a bunch of unburnt wood. Only done it a couple times.

This pretty much sums it up.

A cat can stall due to many things, wet wood, turned too low, failing cat, stove turned down too soon etc. The signs of a stalled cat for me is when the stove is full of fuel that should be giving off enough "smoke" to keep the cat active and the cat goes inactive.(ie a stove full of unburnt wood and a cat in the inactive range)

 

[Ashful]

Interesting post! I assume (with the BK anyway) that it would mean cat thermometer got to active zone. You closed bypass door. Cat thermometer came back out of active zone.

When I've stalled a cat, it's usually been from getting too greedy with turning the stat down a little too far. I had a good fire with cat active turned it down too much, come back hours later to find cat inactive and a bunch of unburnt wood. Only done it a couple times.

I use the term for both of these situations, or more generally speaking, anytime the cat goes active and then drops back out of the active zone before it should. Usually caused by closing bypass or turning down stove too soon, before adequate moisture is baked from your fresh load of wood.

 

[bobdog2o02]

I use the term for both of these situations, or more generally speaking, anytime the cat goes active and then drops back out of the active zone before it should. Usually caused by closing bypass or turning down stove too soon, before adequate moisture is baked from your fresh load of wood.

Regardless of baking moisture out, adequately charring the outside of the wood is what I find to be most crucial to avoiding a crash.

 

[Poindexter]

Ok, the consensus above works for me. Followup question.

Let's say I load the stove, get it hot, get the cat engaged, let it run a little bit, turn it down to say half throttle and go to work. I come back 6-8-10 hours later, I see a clean plume, or nothing visible coming out of my stack. I come in the house, through the stove window I see a bed of glowing coals and the cat is in the inactive range.

I open the door, pull the coals forward, break them up a little bit, close the door. After a while the cat is back up in the active range, without me having added any fuel. I engage the cat, and the cat takes off.

What is the term for that? Normal operation? Stalled burn? Other?

 

[bobdog2o02]

Ok, the consensus above works for me. Followup question.

Let's say I load the stove, get it hot, get the cat engaged, let it run a little bit, turn it down to say half throttle and go to work. I come back 6-8-10 hours later, I see a clean plume, or nothing visible coming out of my stack. I come in the house, through the stove window I see a bed of glowing coals and the cat is in the inactive range.

I open the door, pull the coals forward, break them up a little bit, close the door. After a while the cat is back up in the active range, without me having added any fuel. I engage the cat, and the cat takes off.

What is the term for that? Normal operation? Stalled burn? Other?

It wasnt through the cycle, the coals that you disturbed were "coaling". The coals burn very cleanly and dont leave much fuel in their exhaust for the cat to burn. When you disturbed the coals you let them release more wood gas into the stove and introduced more direct air to the coal pile speeding up the combustion.

 

[Quentin2]

I would say that's normal operation no stall. You had a good burn all the way to the coaling stage. You sped up the coaling stage and got more heat out of it by stirring it up. If you were to leave it alone it would still probably burn 99% of the coals. It would just take longer and have less heat output. A stalled cat if you were to leave it alone you would eventually have a cold stove with splits left.

 

[bobdog2o02]

I would say that's normal operation no stall. You had a good burn all the way to the coaling stage. You sped up the coaling stage and got more heat out of it by stirring it up. If you were to leave it alone it would still probably burn 99% of the coals. It would just take longer and have less heat output. A stalled cat if you were to leave it alone you would eventually have a cold stove with splits left.

Spilts left and a creosote crusted mess

 

[mellow]

Wood was done outgassing, nothing left for the cat to chomp on to keep active. Normal.

 

[Ashful]

One thing that amused me during the disassembly of my cat stove last night was that the firebox was a crusty mess of creosote in every hidden crevice, but the area downstream of the cat was as clean as you could ever want a stove and chimney to be.

 

[mellow]

the area downstream of the cat was as clean as you could ever want a stove and chimney to be.

Same thing I hear from people that have had a chimney fire

 

[Ashful]

Same thing I hear from people that have had a chimney fire

Lol... not THAT clean! But, 2000+ F on the cat does have a way of cleaning things out. Outside of single-wall pipe peaked at 450F during that event, but usually cruises at 250-275F.

 

[Quentin2]

Another definition of stalled cat= wife too hot during the day, instead of turning off blowers and slightly turning stat down she cranked it down. Yep, I came home to a stalled cat 3-4 splits all on the right side, stacked high. WTH! I didn't even realize till later what happened when she told me she was roasting out at 88 deg downstairs in stove room.

 

[Poindexter]

Another definition of stalled cat= wife too hot during the day, instead of turning off blowers and slightly turning stat down she cranked it down. Yep, I came home to a stalled cat 3-4 splits all on the right side, stacked high. WTH! I didn't even realize till later what happened when she told me she was roasting out at 88 deg downstairs in stove room.

Is your wife on the phone with her mom talking about moving someplace where it is going to be hard to keep moose, wild caught salmon and caribou in the freezer? No? You win.