Had to clean the PH again

I burned the PH for a few weeks and it burned beautiful, no problems and great heat. A couple weeks after I switched to some 3-4 year seasoned oak by cat clogged, I cleaned it about 3 weeks ago and it was back to burning nice, last night the flames started dying when I engaged the cat. Sure enough when I checked it was clogged again.
do you guys think:
1) strong draft?
2) could it be the wood?
3) ?? open to any suggestions
3 weeks seems to soon to get clogged again, I know Woodstock says 4-6 weeks but I burned a few weeks with no problem and when I switched wood the problem started, coincidence?

 

Just a guess-
Do you ever use high draft settings with the cat engaged (burning down coals)? I suspect high draft settings make the ash fly, the flames sure whip around when I'm charing a new load.

 

Actually I usually do, I didn't think of that, thanks for the reply, Ill see if not doing that has an effect.

 

No guarantees. Just a theory of mine.

 

I totally love the technological superiority of a catalytic stove, but, I'm strongly leaning to a non-cat stove for the simplicity. Plus, I'm not so good with replacing a $500 catalytic combustor every 3-5 yr., considering we only spend about $<1K/year in fuel oil.

 

Woodstock parts are cheap. A new cat for my Keystone is $150. Glass-$42. Door-$21.
Cats are warranted.

 

I'm on a 2-week, give or take, cleaning schedule during the heavy burning time of year. It isn't clogged after 2 weeks, but just at the point of being able to detect a difference. I just try to work it in around warm spells and when I can stretch out the morning reload. The stove doesn't have to get cold (I think the last match was lit in early December), but it does have to mostly cool down. I've been blaming it on my type of wood (Red Maple) and the fact that I have the occasional piece with a slight sizzle (CSS 18+ mo), so I am trying to get to the 3-yr plan. I do have strong draft, and suspect that doesn't help.

 

I was blaming my wood too but not because its under seasoned but maybe over seasoned or species. But I think Fox might have nailed it, I started burning oak because it was colder, what else happens when its colder? You build up coals so you try to burn the coals down, I'm going to do it with the cat disengaged.
Flamestead, I didn't wait for my stove to get cold either, it was still warm with coals when I took the cat out to clean it. Even if I don't have problems I'm going to check it in 2 weeks to see if that was the problem.
Mike, I don't know of any cat that cost $500, $225 was the cost of a blaze king cat and that was one of the more expensive ones.

 

Mike, You also burn a lot less wood in the cat stove to generate the same amount of heat. Which saves a lot of time in your life...less time c/s/s, less time carrying into the home, less storage area to prepare. And saves on any fuel you are using in your processing. The Woodstock cats cost something in the order of $30 a year, I believe, over their average life. That is the interest on $1000 at 3%. Cleaning the cat is easy...and I may make it easier.

Am thinking of trying shooting a bit of air from a computer keyboard air can through the cat without removing it to see what happens.....If I do it, I'll do it from a small distance to soften the air flow. I know it will make the ash fly around, and some will be sucked back into the cat, but if I can keep that at a minimum, it may take only seconds instead of minutes to service the cat. I'll have to do it with the air and the flue damper shut, so I'll do it on a very samll coal bed, but I have been burning to that lately with my new technique for burning down the coals. Maybe only have to remove it to brush 1/3 0r 1/4 as often....

I decided about two weeks ago to stop burning the coals down with the air all the way open. Once I have the air above 1/2, with a flue damper totally closed, then I open the bypass to disengage the cat. So far, so good. I've made a number of changes in the past 6 weeks, so it will take a while to straighten all consequences of actions, but fundamentally you want to avoid an overly strong draft with the cat engaged, as that is what is clogging the cats. So, if you burn on high with the air quite a bit open, then your cat is going to clog sooner. The more burning you do in cat mode, with the air mostly shut, the longer you'll go without cleaning the cat. And the more you keep fly ash out of the firebox, the longer you'll go. .

I have also started taking the ash out when I rake the coals forward at the end of each burn. Take a few shovelfuls out, takes just a few seconds, as I am using the shovel to rake the coals forward anyway. I push the shovel all the way to the far end of the box, life the shovel, gently dump the larger coals off, then empty the ash into my stainless pail. Really like this practice. Keeps the coal bed burning better at the end of each burn (partly because the air boost hole in front does not end up getting covered by ash), keeps the fly ash down, allows full firebox for loading, makes it easy to manage the ash. And I am only adding a moderate amount of ash to the bucket each time, about every 12 hours so it never gets too hot, and I can go a few days with one of my small buckets, then switch to the other, and dump the first.

This situation only applies to people with a fundamentally very strong draft. Those with normal draft don't seem to have any problem with cat clogging.

 

Hope your not keeping that ash bucket inside, if you are thats a very bad idea.

 

Yes, I know what everyone says. I have done so for 11 years. It is safe and secure in heavy stainless steel with a securely fastened top, protected by firebrick and hearth protection and where no one can reach it. I feel what I do is safer than taking hot coals the length of my home.

 

Sherwood,
Based on my experience, I think you just might have this whole thing backwards... but I could be wrong. By that, I mean it's not the strong draft that clogs the cat, it's when you have little draft and are doing long slow burns. When you open the air all the way up with the cat enganged, you usually get the stove (fire anyway) hot, and when it's hot, the cat burns everything presented to it. On the other hand when the stove is cooling down, and there is not much draft, the cat might not be firing fully, and I think that is when the cat gets clogged. Stuff starts sticking to it, instead of burning.

That is what I see anyway.... Just a thought....

 

Thanks for the info on the price of cats. $500 ish was a number casually thrown out by a local dealer for the most expensive Blaze King combustor he had, which was obviously grossly inflated.

 

In my reading about the cat stoves is they are much better then secondary burn stoves at burning low and slow but as far as saving a lot of wood vs the non cats in something I have not seen claimed any where. One of the reasons we have hybrid stoves now.
Do you have a link?

 

Just trying to make sure you stay safe. The heat isnt realky an issue, as you describe. However, CO is a real danger. Just because you've done something for 11 years doesn't mean its safe. It only takes once.

 

I appreciate your concern. I have several CO detectors AND the top is very well sealed. Also, I burn my coals way down. Nothing much bigger than a spark goes in there.

 

I think Machria is correct. Last year I had a poor draft before extending the flue. I also tended to burn with the air damper fully closed. I had trouble getting the cat to light off and had frequent backpuffing and smoke rolled out the door on reloads, all indicative of a poor draft. Oh - and the cat liked to clog.

This year all those problems have been solved with the additional flue height. I will admit I have been cleaning the cat more often as a precaution, but each time I cleaned it, there was no need - it was perfectly clean.

This year I am also burning on a much higher air setting after WS serviced my stove and said I was babying it too much based on creosote buildup in the connector pipe - they said I needed to crank it up more.

This was the slightly clogged cat:

 

I just cleaned mine tonight, right at the 2-week mark (hit 33 degrees today, but headed back to the single digits tonight). Have been burning hard the past two weeks; cat had a light gray accumulation, but could have gone another week or two (had about one third or less than the photos above, and was much lighter colored).

Has anyone got a nice way to clean the ash in the area between the iconel screen and the cat? I can pull the cat and vacuum some from down in the back of the stove, but don't have a good way to get the whole pathway cleaned.

 

And I can show you a few overly complicated non-cats stoves...

Cats aren't $500 a piece. Even when you are talking about VC's ridiculous cat costs.

 

Maybe an arrow shaft that you can blow through? I havnt cleaned ny PH yet, but the arrow shaft worked great for hard to reach places on my old stove. I use a 28in carbon arrow shaft