Stalling out

[bmwbj]

I know there is alot of VC Intrepid II owner's out there. My question is
my Cat. seems to "Stall out" from time to time, and I can't figure it out.
My draft is super, my wood is dry, and my cat probe directly under the cat
reads around 1100 + when the cat begins to "light off". With a decent load of wood ontop
of a 3" bed of coals, the cat can reach temps of up to 2000 degrees.
Now sometimes with-out any reasons I can see, the cat cools down to 900 or less
and some outside smoke can be seen from the stack. If I crack open the door
ever so slightly, the cat temps will begin to rise and the cat lights-off again.
I know the wood is below 25% moisture and the Cat, stack, and draft are good.
I know I can't be the only one out there with this issue now and then, I'm just looking
for some answers as to find out how to prevent "Stalling out".

Thank you all prior to answering... :-S

 

[Valhalla]

First questions. Has anything changed? How long did your stove run normally, that is before this problem started?

 

[bmwbj]

VAL, This has been an ongoing issues, I just thought I was nuts, but
after putting in a Cat. probe I can monitor it's every move and see
when it's on and off.

 

[karl]

Maybe you're cutting the air back too much.

 

[Valhalla]

I agree. Add some more open throttle to it!

 

[Valhalla]

VAL, This has been an ongoing issues, I just thought I was nuts, but
after putting in a Cat. probe I can monitor it's every move and see
when it's on and off.

From the first day of operation after the install?

 

[bmwbj]

I agree. Add some more open throttle to it!

Val, if I add more air the stove grittle temps will reach well over 800+, and I was under the
impression that you can run cat stoves at lower temps and have the wood smolder some what
because the cat feeds off the smoke. If I open up the air, the fire burns up the smoke
before it gets to the cat.
Now I don't load my stove to the top just for that reason of overfiring the darn thing...3 small splits
are about all I will go as to not overfire. I have also noticed that if I burn for a entire weekend, and my
coal bed becomes a bit much, I will let the coal bed burn down for a while, to about a softball size, than it
really become difficult to get the cat to light off again, even when letting the stove temps come back up.
I seems that the cat works at its best during the first 4 hours of every first start. I only burn nights and
weekends, so the stove does not run steady for long periods. I love this thing, maybe I'm just trying too hard
to make it "perfect" every time I use it. My 25 year old son says "just load it and forget it, stop worrying about
trying to make it perfect." Gotta love kids...

 

[hookspacken]

2000 degrees sounds a bit high for the cat to run at, I typically see 1100-1200 tops. Once it reached 1400, but that was a few years ago. Anyhow, Maybe you arent putting in enough wood to keep the temps up and create enough fuel for the catalyst. I notice that when I put in a smaller load, i dont get the cat temps as high and for as long as when it is chocked full.

 

[bmwbj]

OK, This weekend it is going to be faily cold again...in the teens. I will try loading up the stove
with more wood. I do however have some questions as to how much, and how do I prevent the
stove from getting too hot? I have always had worrys about over firing the beast with too much wood and
no where to turn when she gets too hot. If I cut back the air, will it not smolder and backpuff? Or maybe
the cat will run too hot as well. If anyone out there has the same stove as me, please give me some calming
advise so I don't have to worry anymore. I usually add a couple of small splits every 45min. to an hour or so,
I would love to have it burn longer without fears of overfiring. Thanks all....

 

[hookspacken]

You could try adding larger splits with some smaller splits. the smaller splits you have been burning will burn faster and hotter than a larger one. Usually, after I have a nice coal bed, I will put in a couple large splits, then fil in the gaps and such with some smaller splits and small rounds. If the stove starts to get too hot and you choke it down, it shouldnt back puff as the temperature in the firebox will be high enough that secondary combustion should start immediatly.

 

[Todd]

900 degrees is not stalling. It should be producing plenty of heat at that temp. The cat will start to glow at 1000. If it dips below 500 with a fresh load then it may be stalling. Is that smoke you see whitish, could be steam?

Also have been told continuous firing temps over 1400 can cause cast iron parts to warp or crack.

 

[bmwbj]

900 degrees is not stalling. It should be producing plenty of heat at that temp. The cat will start to glow at 1000. If it dips below 500 with a fresh load then it may be stalling. Is that smoke you see whitish, could be steam?

Also have been told continuous firing temps over 1400 can cause cast iron parts to warp or crack.

Todd, my whole stove is not at 1400 only the cat temp directly under the cat. And yes I have smoke under
900 and its not steam...it's gray and heavy. If I keep my temp at the cat over 1000 it work perfectly.

 

[Todd]

I wonder if your probe is off? That doesn't sound right temp wise.

 

[WidowMaker]

I wonder if your probe is off? That doesn't sound right temp wise.

Dingy, Dingy, Dingy...I think we have a winner...

 

[bmwbj]

I wonder if your probe is off? That doesn't sound right temp wise.

Sorry to bring this up again, but I had it happen this weekend. I was burning the stove all day sat. and sun.
than decided to burn down some coals that I had too many of. Stirring the ash pile up a bit to remove any
un-needed ashes, and emptied the small ash pan that the Intrepid has. The stove was still too hot to touch
300+, I reloaded for a restart on top of the remaing hot coal pile and the wood started burning brightly
again. My stove cat. thermometer read 1000, the pipe read 900, the stove read 500, I shut the door
tightly, engaged the bypass, and the outside stack smoked heavily for the entire load...consiquently the
cat. never lit off again for the entire evening...This is the issue that I'm having. It seems that if I start with a cold
stove, the whole proccess works wonderfully, but if I rekindle in the in the middle of the burn cycle after the
cat cools down, it never seems to work the same again....Am I crazy, or is there a secret to this that I am missing
or am I just doing something wrong.

 

[North of 60]

The way your describing this stove. It sounds as strange as that animal in your avatar looks. Is it your model of stove? I dont know, but your son had good advice to the normal operation of the CAT stoves Iam familiar with. Iam sorry bmwbj that your still having problems. I recall we have had crossed paths a few times. Sounds like your giving it your all with your observations.
I do hope an answer comes along shortly for you. Something is not adding up here, and no Iam not calling you nuts. :coolsmile: I wish I could be there in person to see it in action. All those temps seem to be through the roof. Your CAT should preform at 1/2 those temps. Did you ever have your dealer out to help you deal with this at the beginning as
I cant recall? Again, Good luck North of 60

 

[bmwbj]

North, I do wish you were here to see that I'm not crazy....and I do wish the dealer could help me, but they
when out of business shortly after I bought the stove. I do love the stove, I just wish I can make it work
for me alittle bit better.

Thanks for your help.

 

[Todd]

How old is the cat? Could it be burnt out and need replacing?

 

[Backwoods Savage]

I agree. Add some more open throttle to it!

Val, if I add more air the stove grittle temps will reach well over 800+, and I was under the
impression that you can run cat stoves at lower temps and have the wood smolder some what
because the cat feeds off the smoke. If I open up the air, the fire burns up the smoke
before it gets to the cat.
Now I don't load my stove to the top just for that reason of overfiring the darn thing...3 small splits
are about all I will go as to not overfire. I have also noticed that if I burn for a entire weekend, and my
coal bed becomes a bit much, I will let the coal bed burn down for a while, to about a softball size, than it
really become difficult to get the cat to light off again, even when letting the stove temps come back up.
I seems that the cat works at its best during the first 4 hours of every first start. I only burn nights and
weekends, so the stove does not run steady for long periods. I love this thing, maybe I'm just trying too hard
to make it "perfect" every time I use it. My 25 year old son says "just load it and forget it, stop worrying about
trying to make it perfect." Gotta love kids...

The things that catch my eye are in bold above.

Smoke burning before it gets to the cat. What?
Adding 3 small splits so as not to overfire. Not so good.
Letting the coal bed burn down to about softball size. Wow!
The cat working best the first 4 hours. Naturally.

Perhaps your son is right and you are just too worried. You are not letting the stove operate, you are trying to control every minute....and loading 3 small splits at a time plus softball sized coals....

My suggestion is to burn those coals down first. Quit adding wood when you have a big coal bed. You do not need that big coal bed at all. Yes, you need some coals, but be reasonable. Those coals certainly should not be softball size nor should they be baseball sized. Also, don't worry about the smoke burning before it gets to the cat. Let the stove worry about that and be at peace.

So I'd suggest first burning those coals down before adding any wood. Have only enough coals to get the fire going. Fill the firebox at least 3/4. Char the wood good (maybe 15 minutes or more depending on your wood) before engaging the cat. Dial the draft down. Relax. Let the stove do its thing. When the wood gets to the point where there isn't smoke, or when it is mostly coaled but not fell apart, open the draft at least 1/2 way. After a bit, open the firebox door and with a poker, stir up those coals a bit. Open the draft full and let it burn. Don't worry about heat going up the chimney as at this point that is not a worry. Don't add wood until the coals are burned down.

I sure hope this helps. Good luck.

 

[bmwbj]

Dennis, maybe my wording was incorrect, I don't have "softball" size coals...I have a remaining coal bed that
is about the total size of a softball. I also perform the steps as you mentioned, but sometime the cat. does not
want to relight. This does not happen all the times, but when it does, it is very difficult to relight it
with-out over heating the stove with very bright, heavilt flaming wood.

 

[Backwoods Savage]

bmwbj, while I am not totally familiar with your stove, it seems as though the cat should work similar to the cat in our stove.

In our stove, if you get down and look up through the top of the glass front, you can actually see the cat when it is glowing bright red. However, that thing does not always glow...but it does not mean it is not working.

How do we know it is working? Simply by watching the stove top temperature. Once we engage the cat, the temperature rises fast even though we've cut off most of the draft. Depending on the fire and the type of wood we put in, sometimes the cat will start glowing within a minute and sometimes it simply will not glow. But it is working nonetheless.

Last evening is one good example. I put mostly elm but one good sized ash in the stove. After 15 minutes, I set the draft to 1 (it goes from 1 to 4) and engaged the cat. After about another minute I cut the draft to .5 but found too much flame so went to .25. Not much flame at all now but 30 minutes later I looked and the stove top temperature was at 650 degrees. Yes, the cat was glowing. An hour later though, the cat was not glowing, but the stove top temperature was still 600 degrees.

Rarely do I even look at the cat though as I've learned to just watch the stove top temperature. If the temperature is up, the cat is working. End of my worry. When the stove top temperature drops to 400, that is when I open the draft to at least half way and sometimes I will open it full right then. At this point, there is no smoke as it is all coals. So we extract as much heat as we can from the coals before adding more wood.

When we add wood, we go by what is needed to keep the house at a comfortable temperature. Well, comfortable for me and uncomfortable for most others, especially the ladies. Warmer means more clothing removed. Otherwise we have to wait for summer time to see some skin. lol

During the daytime we do usually only put in 3 pieces of wood and those are usually small. Perhaps 2 small ones and one larger. The larger one has a big knot or is odd shaped so we burn it then instead of when we load the stove. We only fill the firebox at night or if we are to be gone most of the day. We empty ashes as needed but usually that means about every 4th day or sometimes 5 or even 6 days.

One more thing we do is to rake those coals a couple times to help get them burned down. As they burn down, we'll move them toward the front, where the air enters. This helps them burn down faster so we can add more wood.

 

[bmwbj]

Dennis, I do know that the direct flames inside my stove is the only was my stove produces heat. That cat only
cleans the exhaust from exiting smoke out the stack. I can regulate the stove temp. simply by adjusting the primary air.
My secondary air only supplies air to the cat and does not feed the stove. The more flame there is present, the more heat
it produces. The cat only runs on the left over smoke produced by incomplete combustion. It is possible to have very high cat temps with very low stove temps, but if the wood smolder for too long it will back puff. Now you see why I never stuff the stove for fears of overfiring. I guess I will stick to my practices with small fires and burn hot and clean that way.


Thanks for your help. Bob