Ideal Steel catalyst temps

I'm sure this has been hit on a lot before but I haven't found the answer. New IS installed and I've gone through the break in fires. I'm not burning a lot because I don't have a lot of seasoned wood. I'm using some of my 2-3 year old splits that were leftover from the move. I also had an in store credit at menards so I decided to buy 20 packs of eco bricks, or whatever the brand is. Here's the situation, I can easily get the cat probe up to 500-700 degrees and engage the cat. Once I do, I choke the air down and settled the burn down. The black box usually happens, even with the bricks, and the cat temps climb. With the air about 2-4 small notches open, almost shut down all the way, the cat temps will easily climb to 17000-1800 degrees. Stove top, left of the collar, will be 400-450. That's good heat, but there is no way I could open it up more without the cat going much higher. I'm okay with this, except I'd like to get a little more heat from the stove. I'm waiting on the cat to "break in" a little so it's not so hyper active. Will the cat temps in the 17-1800 range hurt it? I've been trying to keep them around 1000-1200. I can rest my hand on the double wall at these temps without any problem at all.

 

Unless my cat thermometer is broken I've never seen it go above 1400 and that's for a very short time. I'm talking 10 minutes until the stove settles in around 1100 to 1200.

 

My cat gets hottest with the draft fully closed. As I open the draft, the flames increase consuming the smoke.
My cat peaks at ~1500F.
Keystone. YMMV.

 

Maybe it's my Condar probe. I'm at 19 hours on 12 bio bricks so on the next load I'll leave the air open longer to keep flames going. I'm probably choking it down too quickly and over feeding the cat smoke.

 

Probe may be off a bit, but these stoves will take off with the right wood and draft. My Condar probe would easily hit 1500 on a reload before I throttled it down. I'm sure it would have gone higher. I replaced the Condar with a thermocouple, and the same flue/STT temps only yield about 1300-1350. I think the Condar was off about 200F.

With dry wood and about 25F outside, I usually get a max STT of around 450 with flue running around 425 (rear exhaust, probe at 12") and cat temp that will peak at 1325 or so with damper at 3rd or 4th notch. If I want max heat, I will leave the damper at first large mark and let the flames dance in the firebox. That usually yields STT of 550 and flue of 475 with CAT anywhere from 800-1000 depending on flame intensity. As the flames die down, the cat will take off on you if you aren't watching it. I filled the box with dry oak last night and set the damper for a long run. My cat alarm went off 2 hours later. One little notch less on the damper settled the temperature rise down, and it still had coals in it this morning. I have my cat alarm set at 1325, so I'm probably a little conservative on that. I think that's why I still have coals in the morning. I think I'll let it run this weekend and see what the peak cat temp actually is.

Bottom line: You can run this stove hard, but I also think you can over fire it if you're not careful. It was too much of an investment for me to risk damaging it, so I'd rather be safe than sorry.

 

I'm jealous of you guys with numbers on your cat meters. I just get active or inactive. I am considering paying for a replacement condar with the numbers!

 

I haven't ran mine yet but from what I've been reading on other posts I think you've hit the nail on the head. Let it run with some secondaries and see what it does. I also remember reading that the compressed bricks like to make the Cat burn a little hotter.

 

I like to see cat temps of 1500 at most...no reason to push higher and risk peeling the wash coat. The Buck at 1500 was still bustin' out big heat. Cat did go high on me a few times, up to 1800+, maybe more than I know since I wasn't watching the stove much after loading at my MIL's house. I did see minor peeling in a couple spots last time I had the cat out. This is a ceramic cat but I have also seen peeling on a metal (diesel-foil) cat. Not sure if anyone has seen peeling in the DuraFoils which are in the newer Woodstocks and BKs. I'm sure it is still possible to peel 'em, though, if you roasted 'em long and hot enough...

You might mix in some other wood with the bricks to keep the peak cat temp down a little. Or go out and cut a bunch of 6" dead trees with no bark left on 'em...that stuff will be about 20%. I know it's winter, but you, braggin' 'bout "forty degrees north," should be out there cutting in shorts.
Woody....38* north.

 

I'm not so sure I've had that expirience. Those secondaries sit right under the cat and I suspect that might be the best way to heat it up. Then you get that tertiary air blowing in. In my opinion that's the magic of the hybrid. The secondaries and the cat play off each other- keeping the other one going.

 

also keep in mind that a fresh cat is VERY active, it will become less extreme with time.

 

Cat was just at 1300 on a load of maple and black locust. Didn't go any higher. Peaked there.

 

I have been mixing in some ash that I have. The cat probe just goes straight to lava when I load the stove. I just loaded the stove again after a 25 hour burn. This load had 3 good ash splits and 12 bricks. Lit off on a coal bed. Secondaries came on fast. Got the typical dancing slow flames and oxy/acetylene torch flames from the secondary plate above the load. I let it get going well, started to choke it down to half, engaged cat and it ramped right up...way up. Probe was almost maxed 1900-2000 degrees. Air choked all the way down, still had very small, lazy secondaries and the cat slowly dropped to 1500. This cat seems really active. Basically uncontrolled. I tried opening up the air to get more secondary flame, cat still stayed high. At one point I opened the bypass, afraid I was hurting something. I will get it figured out. These bricks are nothing to sneeze at. I'll put just a few in the next load with more ash splits. Secondaries when it was straight nuclear in the pic below. Stovetop was 525 and I could touch the double wall pipe without any worry. I'm wondering if my Condar isn't right. I'll boil some water and proof it.

 

pretty sure any cat shouldnt be run at temps anywhere near that

 

Totally agree. That's why I freaked out

 

I did peak under the lid when it was cranking hot and the cat edge was barely orange. The baffle above it wasn't glowing like some pics I've seen. I'm questioning the probe a little.

 

Think I found the problem. I let the probe cool to around 200 and then put it in boiling water for about 4 minutes. This is where it stayed after it climbed.

 

yup, thats the problem. after problems of my own like that you should sendo that probe back and get a new one. warranty issues could result by calibrating your own.

 

Yeah, if it was only orange on the edge, no way it was very hot. 1800 is glowing bright orange, where you can't see the individual cells anymore.

 

Well I was going to suggest your probe was reading high... on the stove top thermo there your 400-450 temp is about average I figure. Cat should be perhaps a bit more than double that temp which sounds in the ballpark. You got some good long burns there that's great. You can definitely get it hotter though if you're stretching it out to 24+ hrs! I know it's counter-intuitive initially but running it with a bit more air may reduce cat temps. Remember with the secondaries going well there won't be much smoke left over for the cat to burn. And the secondaries heat will spread out over the whole stovetop and has to go all the way to the back of the stove and then again all the way to the front until it hits the cat so will have a chance to radiate some of that heat before it hits the cat. I usually run mine in the 400-500 range where your stove top thermo is, but if I am getting it hot for a bit might hit 600-700 but I rarely run it that hard. I remember seeing one of the beta testers hit 800 or 900 I forget exactly there next to the top flue collar. Careful with those bricks though. I burn the Redstone Ecobricks, now called Enviro bricks I think - if that is what you're burning then I am familiar. I've done some pretty big loads and required the air to be fully closed and still pushing 1,000+ on the cat. I even covered the remaining tiny secondary hole with a magnet trying to keep the cat under 1000 for a long burn. That was before I put in a flue damper, but I don't think that damper made a big difference actually.

Sucks you got one so far off. I ought to do some testing on mine. When cold mine seems way lower than the scale would lead you to believe 70F should be at. If you continue their scale down lower I think mine sits at -200F when the stove is cold. But I see it hit 1200-1400 often so I don't think it's really reading low by that much... at least I hope not!