Please explain cat "learning curve"

Don't worry, you're doing your homework now, and it's not even due yet!

All EPA stoves have a learning curve - I'm about to embark on a downdraft-stove learning curve that I had no idea about when I chose my stove.

I'm not a cat guy, but they'll be here soon. You can start with the SEARCH function - that can keep you going for a few months with plenty of reruns. Endless info on this site...

bfunk13 said:

What is it i need to know? As i understand that cat is turned on only
after a good fire is achieved? And to check the cat often, possible replacing
after 3-4 years? ...

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I found this technical information interesting, and it helped me understand combustor behavior better, but it's a lot of info, much more than the bare minimum needed to operate the stove, so be forewarned.

http://www.sud-chemie.com/scmcms/we...yId=5752&preview;=&disposition=inline&lang=en

As a new cat stove owner (Encore 2550), I have read about not "over firing" the cat. What does that mean? In the dead of winter when the stove is cranked up will I need to disengage the cat?

Don't engage cat until blank temp is reached.
Disengage cat every time you reload.
Don't burn coloured paper or other non-pure woodstovey things in your unit.

You can remove the cat and vacuum the crap out every once and awhile. Be careful as it is fragile.
Have no idea when you need to replace the cat. Only had my cat stove for two years.

The stove may smoke more than a non-cat until you get the hang of it. My old neighbour had a Blaze King and he spewed smoke everywhere for weeks. I told him he was an idiot and didn't know what he was doing (we are friends). He finally got it and now he is smoke free.

I'll do my best to explain the use of the cat. at least as how it applies to our stove.

1. Before opening the door to add firewood, disengage the cat. Not difficult as it just means moving a lever one way so it is not difficult to learn. Even my wife has this down pat.

2. After adding firewood, wait 10-15 minutes. At this time you are normally turning down the draft, so, just move that little lever the opposite way as you did 10-15 minutes ago.

3. Forget the cat until the next time you add wood.


Now to add to those instructions, the cat. should not be engaged before the interior of the stove reaches 500 degrees which will read 250 degrees on the stovetop thermometer. But you don't have to worry about disengaging it as the fire cools.

Overfiring the cat. would be overfiring the stove. Don't do it. On our stove, 700 degrees is considered tops (on the stove top thermometer).

On our stove, about the only time we have to wait for the temperature to get high enough to engage the cat is when starting from a cold stove. The time can vary buy you'll learn tricks to speed things up. For instance, turn the draft down once the fire starts or else most of the heat will go straight up the chimney instead of warming the stove.


In a nutshell, as I've posted in the past, my wife can and does tend the stove completely if needed. She can even clean the cat, which takes about 3 minutes maximum. Yes, it is easy. Yes, it is worth it.

Also avoid things like pallet wood that contains galvanized nails, etc.

bfunk13 said:

I have a new Blaze King princess insert sitting in my living room
...What is it i need to know?

Click to expand...

Brad,

My insert is also catalytic, and it's pretty new to me, but the best tip I read about engaging the cat is called the "Five Second Rule."

You're supposed to get the temp up in the firebox before engageing the cat, but it's hard to judge temps on an insert because there's no good place to stick a thermometer. So somewhere on this site a cat insert owner explained that he judges temps by feeling the air blowing out of the insert when fan is on. He developed a "go/no-go" rule for the cat which basically is, when he can't hold his hand in hot airstream for more than five seconds, it's time to engage the cat. I tried this on my insert, and it works great for me too, 100% success. Maybe each brand of stove is a little different, so you might need six seconds, or four. The point is, once you get it dialed in and figured out, it's a pretty simple yet effective way to time your cat engagement.

The second best tip I learned is that once the cat ignites and its temperature stabilizes, say after ten minutes of operation, the cat reaction is self-sustaining. Meaning that the firebox temps may fall below the ignition temp of 500*, but as long as there is enough fuel (smoke) and oxygen, the cat will continue to work. On my insert, this means I can shut the stove down pretty soon after engaging the cat and get long smoke free burns if I want. Very useful for overnite and workday burns.

I think it's worth learning the nuances of the cat combustor because you don't have to burn as hot as a non-cat all the time. This means longer burns, and it's not a marginal difference. For example, my little insert with it's tiny 1.25 cubic foot firebox delivers clean burns of 8 hours when properly managed. Recently I've had three 10 hour burns on very good dry Cherry, finding after 10 hours about two quarts of active coals ready to promptly ignite a new fuel load. Of course, it's not throwing much heat after 10 hours, but still that's not bad for a 15 year old product with an aged catalyst and a beat up refractory package.

Cats rule!

bfunk, here's another easy rule of thumb. Use 10-15 minutes minimum and make sure the wood has charred before engaging the cat. It doesn't take long. Usually by the time you want to close the draft it is time to engage the cat.

Reading you owners manual and referencing to your CAT thermometer will help. BK has a very good detailed instruction info.
Congrats on your new insert.

Just reading all the different threads in this forum will teach you more than you'll realize.

Last year I bought a house with an old top loader. It didn't make sense to me. How can you light or add wood to a burning fire from a hole on top of the fire box. I called the guy who sold me the house to see if the stove really worked.

One night last winter, freezing, I was reading posts here and I got so "fired" up I just went over and conquered that thing. Got my first fire going. I burned all winter and got to know the old fire dragon like an old best friend.

Tomorrow, I'm putting my final connection on my new "used" Regency 3100. It's a different kind of animal that I know will take some burning to get the hang of. Confident, excited and a bit nervous, I'll be starting my new learning curve and will be tapping this website for the collective wisdom of my wood fire brothers.