What did I do wrong with my flue thermometer?

Does it get hotter than that with the cat bypassed?

Nothing. What did you expect it to read? First off, a proper probe meter would read about double, or 400 degrees for the temp of the exhaust. Your temps are what I would expect on the backside of a properly functioning cat.

You should be able to briefly hold your hand on a 200 degree surface. Try your fingertip first. If you're particularly weak, lick your finger tip before touching the 200 degree surface.

So no fire=200 degrees?

Well I dont think its working, should be hotter than that when you have the cat bypassed.

Take the wire off and use a screw through the hole in the middle of the thermometer. Maybe the wire is keeping the back surface of the thermometer from sitting flush against the pipe? I also wonder if that wire was catching the spring wound indicator when it heats up and could of broke it?

Glass is clean? Burns are long? Coals are fine? You are ok I would bet.

My thermometer of that type was bad about "hanging up". But I figure millions of people burn just fine with no thermometer all the time.. so while nice, it isn't the only way to tell if you are burning clean.

If you are really worried about mucking up your pipe.. pull that bottom cap and have a look.. take like 20 seconds.

Those zones are pretty approximate and pretty much not applicable to a cat stove.

mfglickman said:

Highbeam said:

Nothing. What did you expect it to read? First off, a proper probe meter would read about double, or 400 degrees for the temp of the exhaust. Your temps are what I would expect on the backside of a properly functioning cat.

You should be able to briefly hold your hand on a 200 degree surface. Try your fingertip first. If you're particularly weak, lick your finger tip before touching the 200 degree surface.

Click to expand...

Well, it has these "zones" marked on it that say under 300 is like "Danger, Creosote" or some such thing. So I was afraid I was mucking up my brand new liner and tee - but it didn't seem right since the stovetop temps are good and the stove is kicking out good heat, with decently long burns and most wood is burning right down to nothing, with a nice coal bed for each new load.

If the interior is twice that, then I'd feel better.

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Mary, I agree with Todd that the wire might be part of the problem. You did not state where you purchased the thermometer so we are blind on that one. But just to let you know what can happen, as you know, Woodstock includes a stove thermometer with the stove purchase. We had never used one before but I got to liking it so wanted another one. We even received one as a gift. But there was a difference!

Woodstock gets their thermometers from Condar. Rutland is the most common that we find around here and we ended up with two of those. They were a big difference from what the Woodstock thermometer read. We purchased another one from Woodstock and it was only 10 degrees difference at most from the first one. We had checked the first one in the oven and found it to be close. Later we purchased an IR thermometer and it confirmed what we had. The Condar were pretty darned close to the IR. The Rutland were a long ways off. We put those in the trash.

As for a difference in temperatures between the stove top and flue, yes, there will be a big difference. The flue simply will be at a lower temperature except when you reload and before you engage the cat. With the flue thermometer, we tend to get it to 400-500 and the stove top to 350-300 before engaging the cat and that seems to have worked the best for us.

Is there any chance (it is hard to tell from the pic) that you have the thermometer on a stainless steel insulated chimney tee? The exterior of those will never get over 200F.

Test in a 350 degree oven then you shoud know if its working.

mfglickman said:

unhdsm, yes it's on the tee. It's either that or the liner cause that's all I can reach (and I can barely reach the edge of the liner.

Mary

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I was less concerned that it was on the tee as I am making sure the tee is not Class A and insulated. In that case, I would not expect surface temps to be hot at all.

I have an almost identical setup to yours, rear-vented to stainless tee to flex liner. I have a surface thermo lying on the tee snout directly behind the flue collar. It might register 400-500 when starting a load with the bypass open. After it's up to temp, the bypass closed and cat engaged, stove top will go up to about 450, temp on the pipe is around 350. So 200 where you have the thermo (further away) might be about right. The flue thermo is useful on startup/reload to make sure you're bringing the stove up to temp in a controlled fashion and not stressing your chimney or stove by firing too hot. The stove top temp is going to lag behind what is actually going on in the firebox, so the flue thermo will give you a more accurate picture early in the burn. Next time the stove goes cold you might want to screw that thermo to the pipe. Stainless is hard to drill though, and the drill bit has to be the right size or you'll have trouble getting the screw to thread in...

mfglickman said:

Guess I'll have to run on instinct sooner than planned

Click to expand...

You can certainly do that. You just have to watch the fire during startup/reload. You can judge pretty accurately how hot the firebox and flue are by how the flames look; A roaring fire looks different than the slow-moving, lazy flames of a moderate fire. With the smaller window of the Fireview, I have to get down low or bend over to see how hard the flames are hitting the combustor pan and scoop...

Yes, the stainless T outside temp will not show any thing much hotter.
I bought the Condar probe and drilled the hole in the T in same place you have yours. Because it is stainless, I had to make a bracket and screwed bracket to ss t and then the probe sticks to bracket. My probe will show 1000 degrees and the outside of T with IR gun shows 200. After I engage the CAT, the probe will run around 400 - 900 depending on the air control.

These pics were taken 20 minutes after engaging CAT and temps inside are 900
The bracket is just a simple electric box support and holes were already in it so I just bent it to form curve same as the T
I know the probe should be 18 inches above stove but that could not be practical with my stove in fireplace. I will run the probe temps up to 1400 and stove air handle 3/4 open until stove top is 500. Works great but I have to stay near stove as it warms up very fast. At 1400 I have seen the liner start to glow red about a foot above the T and that has happened about 3 times as I was testing the flue probe and the reaction of flue itself.