Something Different Happened with the Catalyst Lastnight..

[hookspacken]

I had just loaded up the stove. activated the catalyst, turned the air down till almost closed and started to watch TV. I always check the flame every once in a while (drive my wife nuts, I am always fiddling with the air) well, when I looked after about 15 minutes or so, there was no flame, but it looked like there was a light on in the stove. The cat was glowing orange with no flames in the firebox. I watched this for a while and the cat temps continued to rise, 1300, 1400, 1450, 1500..then I got nervous and diengaged the cat and immediate flames eurupted.
It was definatley different, I had never seen anthing like that. You could watch the smoke drafting up to the cat, a very small flame running around the cat air supply ringjust under the catalyst. Anyone ever experienced anything like this before? It was kind of cool to watch.

 

[Andre B.]

Now I have no experience with cat stoves but what you describe is how I would expect them to work.

All kinds of info on catalytic and surface combustion.
http://tinyurl.com/228gb9 (tiny by Mo)

 

[treeman08]

I am not an expert on catalytic stoves, but I have been burning my Blaze King cat insert for a couple of months.
My understanding is what you saw is pretty typical of what I am doing. Blaze King has a thermostatic air control, but with the cat it is designed to not have active flames in the box. My fire often looks to be smoldering but there is no smoke from the chimney. The cat is burning the smoke. When the fire is hot I have stove top temps at 450 to 500 and a glowing cat. My cat thermometer does not have temperatures. It only has active and inactive zones, but based on the normal lightoff thmperature of 500 I would say it regularly runs in the 1000 to 1500 degree range (orange Glow).
It is my opinion that the cat stoves gives a longer, more efficient burn, but sacrifice the fire view.
hope this helps. good luck

 

[hookspacken]

I usually have really lazy purple-ish flames and some secondary flame combustion going on, but this is the 1st time i had no flames for that lenght of time. So you regularly burn with no visible flame?

 

[Rhone]

With a cat stove that's possible. The cat is self sufficient once started so even if the logs are smouldering or the firebox temps are dropping the cat can still be doing it's job and maintaining temps higher than the stove.

I don't think zero flames is a good thing, cat stoves are not flaming beasts but should have a flame. Normally, the cat burns the gases that weren't burned in the stove. It sounds like, since you didn't have a flame your cat was burning the normal AND secondary gases. I'd imagine that shortens the life of the cat. Since the cat impedes air flow slightly, that may be the reason you got flames once you disengated it and let the air flow freely which rekindled the fire.

 

[ozarkjeep]

ive witnessed somewhere between what you and treeman have said.

if I get it really hot first ( glowing) top temps to 500-700 degrees, then the cat will stay hot, with or without the glow, for a long time as long as there is something being gassed off inside the firebox.

at any time during this type of burn, if a flame licks up onto the face of the cat, it will glow in that spot again.

usually over an hour of those blue purple, ghostly flames whisping around.

BUT, I have to get the cat really hot initially to get that process going, and it lights faster depending on how I stack the logs. it lights faster, with the ends of the splits closer to the cat, so the gases and flames are directed into the cat combustor.

I do not think my combustor is operating as well as a new unit though, it goes out too early I think, cant burn at temps below 600 or 700 degrees.

I usually have really lazy purple-ish flames and some secondary flame combustion going on, but this is the 1st time i had no flames for that lenght of time. So you regularly burn with no visible flame?

 

[treeman08]

Maybe I stated that incorrectly. I am talking about the glow after I have had a hot fire (stove top temp 450 to 550). When turn down the thermostatic air intake, the flames go out after a short period (10 to 15 minutes), but the cat continues to glow for an hour or so without visible flames.
It is normal when I build the fire for overnight burn and damper it down that I have 400 stove top and 700 to 800 cat temp, and have to turn out the lights to see the coals glowing red to convince myself that the fire is still burning. In the morning I will have a couple of dark logs, stove top at 250 to 300, cat at 400 to 500. I turn up the air, and get glowing coals and soon flames. After a shower I add a couple of large splits, eat breakfast, and then turn the air back down to start the slow burn over again.

 

[ozarkjeep]

that solidifies my thoughts of my cat not working 100%.

thank you for the breakdown!

Maybe I stated that incorrectly. I am talking about the glow after I have had a hot fire (stove top temp 450 to 550). When turn down the thermostatic air intake, the flames go out after a short period (10 to 15 minutes), but the cat continues to glow for an hour or so without visible flames.
It is normal when I build the fire for overnight burn and damper it down that I have 400 stove top and 700 to 800 cat temp, and have to turn out the lights to see the coals glowing red to convince myself that the fire is still burning. In the morning I will have a couple of dark logs, stove top at 250 to 300, cat at 400 to 500. I turn up the air, and get glowing coals and soon flames. After a shower I add a couple of large splits, eat breakfast, and then turn the air back down to start the slow burn over again.

 

[treeman08]

Your welcome... I am just sorry I did not make it clear in the first place.
My cat had better be close to 100% as it is only 2 month old.
I have not seen any build up on either the cat surface, or the perforated plate in front.

 

[ozarkjeep]

I have never had the cat glow without flames whisping up on it constantly.

smoke alone wont do it.
it WILL maintain a slightly higher temp ( 495-550) stove top temp ( right behind the cat) but it will not continue to glow, and climb in temp without flames in the firebox.

with big flames in the box ive seen 940 stove top temps, BRIGHT cat glowage, it was working then!
haha

Your welcome... I am just sorry I did not make it clear in the first place.
My cat had better be close to 100% as it is only 2 month old.
I have not seen any build up on either the cat surface, or the perforated plate in front.

 

[woodheatisgood]

I had just loaded up the stove. activated the catalyst, turned the air down till almost closed and started to watch TV. I always check the flame every once in a while (drive my wife nuts, I am always fiddling with the air) well, when I looked after about 15 minutes or so, there was no flame, but it looked like there was a light on in the stove. The cat was glowing orange with no flames in the firebox. I watched this for a while and the cat temps continued to rise, 1300, 1400, 1450, 1500..then I got nervous and diengaged the cat and immediate flames eurupted.
It was definatley different, I had never seen anthing like that. You could watch the smoke drafting up to the cat, a very small flame running around the cat air supply ringjust under the catalyst. Anyone ever experienced anything like this before? It was kind of cool to watch.

Hello all. I'm a wood burning newbie but have absorbed lots of information from the forum and hearth.com in general. Thanks for all your help!

Regarding hookspaken's orignal post, I've had that exact thing occur to me before. I was burning nice and low with the dark, translucent bluish purplish flames rolling about. There was no real flame coming off the wood; the flames were at the top of the firebox away from the wood. Combustor temp was at about 1100 or so. Then the fire went out and almost immediately the thermometer rose and the combuster started to glow brightly. I can't remember what it went to, but it didn't reach the "too hot" portion of the combustor thermometer. It was a little alarming, but it didn't stay there very long. Maybe about 10 minutes.

Obviously the catalytic combuster was being fueled by the extra smoke from the smoldering wood. But I'm beginning to wonder about the wisdom of using the combustor as a main source of heat with a really low (or smoldering) fire and whether or not it's overly hard on the combuster. Another question is whether it does this routinely overnight when we're sleeping. It sure helps on fuel economy though and the burn was still smoke free.

An opinion from a dealer which supports this method of burning in a catalytic stove can be read here.

Any opinions from seasoned (pun intended) cat stove operators?

 

[begreen]

Welcome WHiG. I don't have a cat but am curious about your stove. Can you post a picture and maybe a link to the manufacturer's website?

 

[elkimmeg]

I have two Cat stoves burning as I type 6 degrees outside my furnace has not come on yet this year for heating
Cat combustor stoves do take a little learning but I find mine with thermatically controled secondary air less work
bring the stove up to temp let the wood get to the second phase of burning Chared throw the damper and thats it
for over6 to 8 hours of produtice heat.. Productive heat to me is stove top temps above 400.

there is a company selling replacement Combustors about 1/2 the price of OEm replacements They claim iginition
at 380 degrees instead of 500/550 this is an increase of 25% wider range Cat Combusters work in. I am using one
now on its second year it works great.,For a small stove in my familly room I get a realistic 6 hours of productive burning.
the Stove model identicle to my cat but non cat 3.4 hours if luckey productive burn times, so the Cat really takes this small
stove to another level.

We have had epic debates here Cat vs non Cat Stoves There is a super cat developed by VC, that is made of stainless steel.
So far the cost to manufacturer is too much to bring it to maket. It is susposed to be much more effecient and extend the
range further than anything on the market today. When is does come to marke,t I hope I can install it in my two stoves

 

[hookspacken]

Elk, on average, how long do you run your stove in bypass mode to get to the second stage of burn, the charred stage?

 

[homebrewz]

there is a company selling replacement Combustors about 1/2 the price of OEm replacements They claim iginition
at 380 degrees instead of 500/550 this is an increase of 25% wider range Cat Combusters work in. I am using one
now on its second year it works great.,For a small stove in my familly room I get a realistic 6 hours of productive burning.
the Stove model identicle to my cat but non cat 3.4 hours if luckey productive burn times, so the Cat really takes this small
stove to another level.

Can you tell us who? Good for future reference. Plus, I have a friend who needs to replace the Cat in his VC model 2140.

 

[woodheatisgood]

Can you tell us who? Good for future reference. Plus, I have a friend who needs to replace the Cat in his VC model 2140.

Could it be these?

www.stovecombusters.com

 

[elkimmeg]

Stove combustor.com

elk, on average, how long do you run your stove in bypass mode to get to the second stage of burn, the charred stage?

Thats hard one to pin down wood sizes varry so much as well as wood species and moisture containt

On start up the most omrortant thing to get a good bed of coals 3 decent splits burned to coal stage unless the stove is getting too hot then I dampoer it engaging the cat

Once 500 to 650 is established especially 650 I cut the primary air down let it burn a bit more 5/10 minutes I want to establish the temp so that secondary air will adjust itsself to where I want to run the stove I them engage the cat good bed of coals and dry wood 10/20 minutes I will check it a half hour later to adjust the primary air to get it to run where I want it


ITs finally real cold so I want to run it around 600 degrees griddle top temp by doing this I get more heat but reduce the productive heat range to 7 hours and 5 on the smaller stove
I can live with that being over 67 degrees better yet over 70 and no furnace kicking in..

On occasion I do lift the top to look at the charing/ burning stage, to confirm its time and ready to engage the cat. This does not take a great deal of skill to achieve long smoke less heat

 

[ozarkjeep]

Hey Woodheatisgood!

can you post a full sized pic of that avatar?

that looks identical to the placement and configuration of my own combustor in my EarthStove.

Id like to see more of it, it may help me fine tune my usage

I had just loaded up the stove. activated the catalyst, turned the air down till almost closed and started to watch TV. I always check the flame every once in a while (drive my wife nuts, I am always fiddling with the air) well, when I looked after about 15 minutes or so, there was no flame, but it looked like there was a light on in the stove. The cat was glowing orange with no flames in the firebox. I watched this for a while and the cat temps continued to rise, 1300, 1400, 1450, 1500..then I got nervous and diengaged the cat and immediate flames eurupted.
It was definatley different, I had never seen anthing like that. You could watch the smoke drafting up to the cat, a very small flame running around the cat air supply ringjust under the catalyst. Anyone ever experienced anything like this before? It was kind of cool to watch.

Hello all. I'm a wood burning newbie but have absorbed lots of information from the forum and hearth.com in general. Thanks for all your help!

Regarding hookspaken's orignal post, I've had that exact thing occur to me before. I was burning nice and low with the dark, translucent bluish purplish flames rolling about. There was no real flame coming off the wood; the flames were at the top of the firebox away from the wood. Combustor temp was at about 1100 or so. Then the fire went out and almost immediately the thermometer rose and the combuster started to glow brightly. I can't remember what it went to, but it didn't reach the "too hot" portion of the combustor thermometer. It was a little alarming, but it didn't stay there very long. Maybe about 10 minutes.

Obviously the catalytic combuster was being fueled by the extra smoke from the smoldering wood. But I'm beginning to wonder about the wisdom of using the combustor as a main source of heat with a really low (or smoldering) fire and whether or not it's overly hard on the combuster. Another question is whether it does this routinely overnight when we're sleeping. It sure helps on fuel economy though and the burn was still smoke free.

An opinion from a dealer which supports this method of burning in a catalytic stove can be read here.

Any opinions from seasoned (pun intended) cat stove operators?

 

[woodheatisgood]

I don't have a cat but am curious about your stove. Can you post a picture and maybe a link to the manufacturer's website?

Hey Woodheatisgood!

can you post a full sized pic of that avatar?

that looks identical to the placement and configuration of my own combustor in my EarthStove.

Id like to see more of it, it may help me fine tune my usage

I will post a picture or two when I get home today or tomorrow. I've got plenty to choose from.

The model, which is in my signature, is no longer made. The company, which was originally called Ultimate Heating System, changed to Ultimate Stoves, Spas and Patio and apparently closed in 2004 or 2005. It was located in Fresno, CA where I live. I've never seen or heard of it before. I wonder how many of them were made.

The previous owners of the the home we purchased in 2005 picked it up in 1994 so it's got some mileage on it. The combustor flame shield is a bit beat up (I bet from big logs crashing into it during reloads), and it could use some touch up paint here and there. The gaskets are not too bad though. The only thing that concerns me is if I need replacement parts. What do I do then?

I lightly brushed and vacuumed the face of the combustor a week or two ago and it made a huge difference in performance. The cat now increases temp faster, holds temp longer and reduces draft less than before. Overall the fire just burns easier and longer now. I have no idea how old the cat is, but it looks to be in pretty good shape (completely intact, light brown color) although the stove doesn't go into a smoke-free burn during and smoky period of the fire until the cat's in the 850˚-900˚ range. Does that sound about right? I did notice a small gap in the gasket around the combustor when it was cold. I don't know whether or not it expands to fill the gap when hot. Anyone?

Some manufacturer's specs off the top of my head:

3.0 cubic feet firebox
3.8 grams/hr
6-12 hr burn time

That's all I can remember right now...

Ozarkjeep, my combuster is long and skinny and positioned right above the firebox baffe just a few inches behind the door behind a perforated metal flame shield. A pending picture will be worth a thousand words...

 

[ozarkjeep]

hey thanks for the run down!

My combustor is 2.5" x 15.3" rectangular, positioned very nearly where yours is, there is a born tube with holes right in front of the combustor in my stove.

I have learned that a clean cat is a happy cat too, I remove it and blow it out with a leaf blower ( I know, I know, not good) but it works better afterwards.

I get smoke out of mine also unless its really HOT.

I dont have a cat temp probe, just an infrared temp 'gun' to check stove top temps with.

I think mine is old, and showing some wear, it wont stay lit at lower temps, and it nearly takes flames licking into the flame guard to get it ignighted.

cant wait to see the pics!

 

[Mo Heat]

... although the stove doesn't go into a smoke-free burn during and smoky period of the fire until the cat's in the 850˚-900˚ range. Does that sound about right?

Yes.

I did notice a small gap in the gasket around the combustor when it was cold. I don't know whether or not it expands to fill the gap when hot. Anyone?

I don't think it should have a gap. Some smoke will bypass the combustor.

 

[elkimmeg]

StoveCombustors.com sells the sermanic gasket take that wraps around the combustor so smoke does not by pass it

 

[woodheatisgood]

Okay, for those interested, here are some pics of the Ultimate Heating System BV. The object to the left of the cat thermometer is a pot of soup heating up. Why not? It only took 5 minutes.

Here are some key specs since there's no online information about this discontinued insert:

Weight: 450 lbs.
Log Length: 22 1/2 inches
Flue opening: 8"
Firebox volume: 3 cu./ft.
Blower: 220 CFM
Heating Capacity: 1,200-2,500 sq.ft.
Burn Time: 6-12 hrs.
Emissions: 3.8 g/hr

A monstrous beast it is indeed, especially since our home is only 1485 sq.ft. As I had mentioned before, it was installed as new in 1994. A professional installation (I have the original receipts), but I haven't seen behind it or down the chimney yet.

Enjoy and be warm from WOOD!

 

[ozarkjeep]

cool.

thanks for the photos, I need one of those cat probe temp things, ive got a hole there too, except mine is covered by the surround.

that appears to the the same cat combustor unit mine uses ( actually 2 units end to end), and a very similar configuration to the larger brethren to mine ( Earth Stove BV400)