Cat temperature probe

[Ashful]

I ran my cat stove last year without any cat temp probe or stove top thermometer. Having always owned open fireplaces and cooked on charcoal, my belief was that wood burning was one aspect of my life that could/should remain unscientific. You folks have ruined my blissful ignorance.

So, cat temp probes...

1. Why buy one?
2. Do you use one on your cat stove?
3. Will it really improve my burning experience? Do most folks even know how to use this data?
4. What to look for when buying one?
5. Is a stove top thermometer a useful compliment or replacement to the probe?

I suspect I know the answer to several of these questions, but am interested in what the experienced cat stovers have to say. In my case, both cat stoves are installed in fireplaces, and have cat probe holes in the rear, so I'd be looking for something with remote display, if i do this.

 

[pen]

Using one is like adding a tachometer to a vehicle without one. I've done that several times on vehicles w/ a manual transmission that didn't have one from the factory. On the one vehicle, I thought I had it wound right out at X pitch of engine noise, and I had1500 rpms shy of that engine's redline. On the other, I was 500rpm over. Other times, I pretty much knew the mark myself.

The same thing can happen here. In general, it's just a tool that you can use to compare against you burning practices. If you choose to accept it's readings or ignore them, will still be your option after installation. The advantage however is that you will be able to make an informed decision in regards to accepting the temp probe (or stove top thermo's) readings or not.

At the end of the day, if parts of the stove are not starting to emit light, and your chimney is not readily gaining creosote, you probably aren't too far off the mark. What it may do for you is help you to slightly tweak the times when you engage the cat and/or adjust the air which in turn could give you a longer cat life and some wood savings.

For me, the main reason I use them is for the wife. She can look at that fire day in and day out, and still adjust the thing poorly based upon the fire's appearance and general feel next to the stove. But, with the thermometer(s) on the stove, and some guidance (a temp cheat sheet she can look at), she runs it like a pro.

When it comes to thermometers, for the money, I'm ok with Condars (although I will say I have not used their cat probe, I have used several other probes and stove top models of theirs).

pen

 

[Ashful]

I like the analogy, pen.

With regard to the Condars, my stoves are backed up tight against a wall inside a big fireplace, and the probe hole is in the rear, so I need to go with a digital / remote display unit. Since I already work with Thermocouples, and have my own K-type meter, I'm thinking of just picking up some K-type thermocouple probes:

http://www.omega.com/ppt/pptsc.asp?ref=HJMTSS&Nav=tema07

Any thoughts? K-type measurement range is -454*F to +2501*F. Sure is cheaper (and more accurate) than any of the stove-specific products I've seen, although I'd need some guidance on what diameter and tip size might work best for this application.

 

[stoveguy2esw]

i ran one of our cat stoves for several years in my own home and found having a cat probe installed was extremely helpful (remember i do this for a living and stil used one at home) i found that i could almost "dial a yield" using the draft controls load sizes and the probe. like pen said , its not a "gotta have" but its definately a "nice to have"

 

[jharkin]

I believe it depends on the stove also. I use the Condar digital probe on my Encore, and would never want to be without it now. In the VC design with the cat in the rear of the stove, the stovetop temp is not a reliable indicator of cat temp and its possible to get that thing thermonuclear 1800+ when the griddle is within reasonable limits. With the probe I know for sure, I watch it and if it ever gets to 1650 I shut everything down to cool it off. If I wait till its over temp to react it can take a long time to settle. If the stove gets to the point that something inside is glowing its already been deep into the danger zone for too long.

OTOH, from what Ive read stoves with the cat at the top like Woodstock and Blaze King show a much more direct relationship between catalyst and stove top temp so this might not be a concern.

 

[Todd]

I like cat thermometers, it gives you a lot of information and lets you know whats going on in there. The Woodstocks need a good cat probe imo because the soapstone top lags way behind the internal cat temps. It's also a good tool to monitor overfire temps, you should try and keep the cat below 1600 for longer life and less chance of internal warping.

If you have the probe in the rear of the stove maybe hang a mirror back there somewhere so temps can be seen better. Thermocouples are much more accurate because the condars react to the radiant heat off the stove top but can still be used as a good guide.

 

[charly]

Wondering if I should get a probe for my new Fireview. Folks at Woodstock said it was not necessary, running the Fireview was kind of cut and dry. Didn't even look where you would insert the probe.

 

[stoveguy2esw]

biggest advantage i see is having a clear indication that the cat is active during startups, this prevents premature banking with a cat that is not yet fired off which isnt the greatest thing to do to a cat repeatedly. also would show overfire of a cat without the guesswork of a surface thermometer which may not indicate accutrately what a cat is firing at

 

[mellow]

I felt like I was burning blind not having a cat probe. It makes a world of difference knowing EXACTLY when you can close the draft and light up the cat and what stage of burn the cat is in. I would love to have a digital probe on mine that I could see the numbers from the couch in the dark.

 

[Todd]

Wondering if I should get a probe for my new Fireview. Folks at Woodstock said it was not necessary, running the Fireview was kind of cut and dry. Didn't even look where you would insert the probe.

The Fireview has a hole on the left rear of the stove for a cat probe. But I don't think it's in the right place or even close enough to the cat to get accurate readings. I think a couple people have drilled through the top to get a better read. I could never bring myself to do this when I had my Fireview.

 

[Ashful]

Not relevant to the OP, but couldn't you just snake a hi-temp thermocouple wire thru the stove to the right location, from their access hole? Thermocouples (and meters) are mighty cheap, compared to what the stove manufacturers sell.

 

[Woody Stover]

charly said: ↑

Wondering if I should get a probe for my new Fireview. Folks at Woodstock said it was not necessary, running the Fireview was kind of cut and dry. Didn't even look where you would insert the probe.​

The Fireview has a hole on the left rear of the stove for a cat probe. But I don't think it's in the right place or even close enough to the cat to get accurate readings. I think a couple people have drilled through the top to get a better read. I could never bring myself to do this when I had my Fireview.

The probe is 8" long, so the temp at the cat doesn't seem to make it to the dial. I use it more as an indicator of the temp in the top/rear of the fire box near the flue exit. I also have a surface thermo lying on top of the rear-exit pipe. When I have the "cat" probe reading around 1000, the exit-pipe temp will be 600-700. If I run the stove there for about ten or fifteen minutes, the cat will light off immediately when engaged. The stove top meter lags way behind because of the buffering effect of the soapstone, so that is more of a "cruising" thermo. The manual says to engage the cat when the stove top gets to 250 but using the other thermos I can usually light off the cat with the stove top at 220 or maybe a little lower. I would certainly like to know what the actual temp of the cat is so that I could avoid getting it too hot. As it is, I have to guess at how hot the cat is by how brightly it's glowing. I, too, am reluctant to drill a hole in the top of the stove but that would shorten the probe considerably and probably give a good reading. My Dutchwest probe is only 1.5" long and goes through the top of the stove, right on top of the cat.
The back of the stove is even with the fireplace opening so at first I used a mirror to see the face of the dial, which points rearward into the fireplace. Later I bent a paper clip around the bolt head in the face that aligns with 1000. That way, if the probe spins a bit in the hole, I can still see where 1000 is. I can see the temp needle from the back of the dail as it approaches the paper clip, without using a mirror. If the light is low in the house, I might have to use a little flashlight to see it.

 

[rideau]

I like the analogy, pen.

With regard to the Condars, my stoves are backed up tight against a wall inside a big fireplace, and the probe hole is in the rear, so I need to go with a digital / remote display unit. Since I already work with Thermocouples, and have my own K-type meter, I'm thinking of just picking up some K-type thermocouple probes:

http://www.omega.com/ppt/pptsc.asp?ref=HJMTSS&Nav=tema07

Any thoughts? K-type measurement range is -454*F to +2501*F. Sure is cheaper (and more accurate) than any of the stove-specific products I've seen, although I'd need some guidance on what diameter and tip size might work best for this application.

Woodstock posted a video on their PH blog where they were recording cat temps with thermocouples...you could certainly call them for guidance on diameter and tip size.

 

[charly]

The Fireview has a hole on the left rear of the stove for a cat probe. But I don't think it's in the right place or even close enough to the cat to get accurate readings. I think a couple people have drilled through the top to get a better read. I could never bring myself to do this when I had my Fireview.

I'll just pay attention. Look up inside to see if she's glowing. Basically that's what I was told to do. Keep it simple. Yes I wouldn't want to drill my stove either. If it was that critical, I'm sure woodstock would have had it all set up with a probe.

 

[Ashful]

I'll just pay attention. Look up inside to see if she's glowing. Basically that's what I was told to do. Keep it simple. Yes I wouldn't want to drill my stove either. If it was that critical, I'm sure woodstock would have had it all set up with a probe.

I don't know how you folks see your cat. Mine's buried behind a refractory panel, which is then buried behind a cast iron plate. No way to see it.

What is the typical diameter of a cat probe thermometer? The Jotul 12 manual describes the install procedure as, "spin a 1/4" drill bit thru the refractory at the cat probe access port on the back of the stove..." Should I assume they're typically 1/4" diameter? I'm planning to buy one of these thermocouples (3.5" long) to remotely do my cat temperature monitoring.

http://www.omega.com/ppt/pptsc.asp?ref=HJMTSS&Nav=tema07