Progress Hybrid cat question / smoke smell

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3fordasho

Minister of Fire
Jul 20, 2007
1,038
South Central Minnesota
Couple questions for other PH owners- How often are you cleaning your cat? Last night I noticed more smoke smell (not from reloading) and noticed the flames were really dying after closing the bypass... a sure sign the cat is getting plugged with fly ash. It's only been a month or less since I last cleaned it and it was plugged then from a short last season (installed stove last Feb) I do have the new screen set up and I clean that everytime I remove ash from the stove. Also I rarely see stove top temps 400f or over- is that normal or are these signs the cat is not working correctly? I don't see smoke from the chimney but the cat also likes the stall easily, I must maintain 400F flue temps or it will stall and I will see smoke. The cat in the fireview has never plugged up this easily or quickly. The wood is not an issue - split and dryed for at least 3 years, pulled from a covered wood shed. The cat is the original shipped with the stove, but only about a year old now.

Smoke smell (not a reloading/door open issue)- I've replaced the door gasket several times, and it seems better everytime I do it but it does not last - either the gasket relaxes or it's coming from somewhere else and I just think it's better after replacing the gasket. A partially plugged screen or cat makes it much worse so I will be checking those everytime I clean out the ash from the firebox. Woodstock suggested keeping more flame in the box and not to shut the stove all the way down (no flame). I've been following this recommendation and while it does help I've had several times the smell was present and there was plenty of flame in the box. Looking for suggestions here, maybe need to plug some roll pins as mentioned in another thread?
 
I only clean my cat once during the season and once after the season. What's weird is when I had the original screen, the screen would gunk up all the time. The new screen doesn't seem to catch much flyash because I rarely have to brush it. This hasn't led to a clogged cat either. I just cleaned mine a week ago for the first time this year and it had a bit of buildup but not bad at all.

I just don't know about the smoke smell. Some people seem to get it and some don't. You could look into the roll pin issue. Maybe that would help.

Your are running the original steel cat. Some of those cats had some real problems with stalling and lighting at all. They have since changed their manufacturing process on the cats. I would monitor your cat's performance with temps, etc. for a while. If it is not working properly, it is under warrantee.

As for your stove top temps: Where are you measuring and what is your top setup (e.g. original stone top, original cooktop, cooktop with heat shield)? People have reported much lower stone top temps with the shielded cooktop.
 
I have the first version of the cooktop installed, no heat shield. I have a rear flue setup so the thermometer is on the blockoff plate for the top flue (has the stove name cast into it)

The cat plugging so quickly is what has me questioning things, 6 years with fireviews and I've never experienced the issue with those, and they still have the original coarse (expanded metal) flame quard, not the newer style screens. So it has me wondering if the cat is not getting up to temperature.
 
You have the same top as I do. If you're running largish loads, you should definitely be seeing over 400 on the stone top. I can't say for sure where you're measuring because I top vent, but I would sure think that area should be getting hotter.

If your screen is installed properly, I'm not sure why your cat would be plugging up so fast. It could be because it's not burning properly so it's not cleaning itself.
 
Lately I've been filling the stove with Oak and honeylocust but most of it is still only 16"(filling so I can't fit another split) I do tend to run the stove draft in the "almost" closed position but always try to keep some flame in the box.
 
I've had my PH now for 7 weeks. After 4 weeks, I took the CAT out to check, and it looked exactly the same as the day I intalled the stove, which was suprising to me after the raging infermo's that go on in there, hard to believe anything in there looked the same. Nothing on the screen either.

Anyway, Monday evening I had a cold stove for the 1st time in a whil, so I dumped the ashed and checked the CAT again just for the heck of it, and again there is nothng on, in or near it. However, I did notice there is a slight bend in the top of the frame on it, I took a pic and am sending it to Woodstock to check if ok/normal. But I have yet to see anything get on/in/around the cat or the screen at the top of the firebox. I burn both fully closed for long slow burns sometimes, but mostly with the air slightly open.

As for stove top temps, are you SURE you don't have the heat shield under the cooktop? Sure sounds like you do temp wise. I NEVER see the top temp go above 300-350. I've seen the top flue colar get to 400+, but never the stove top itself.

One question for you, what makes you think the "CAT has stalled"? How do you know? I hear this here often, but wonder how you would actually know such a thing, you can't see it. The only thing you can do is monitor the flue gas temps, and if they suddenly drop by 50 or 100 degree's, that ussually indicates the cat is working. But other than that, you really don't know if it is or not.

Lastly, wood smell. If I put my head and nose directly over the stove, as close to the pipe as I can get without getting burned... I can smell a slight wood burning smell. I don't smell it in the rest of the room. I attribute that to the fact, we are burning wood, and alot of it. While the stoves are termed "airtight", we all know they really are not completely 100% "airtight", probably more something like 99%. So the question here is, when you say you smell wood, do you smell wood all over the room, or just right at the stove when you sniffing around it?
 
Oh, one more thing, what keeps making you change the door gasket? Is it vissibly leaking or something?
 
Stalled cat after reloads = stove top temp at 250F minimum and the flue drops around 325-350f - I'll go outside and see smoke (not steam) and smell it outside. To solve I reopen bypass for several minutes, get active flames established in the box, close bypass and cut draft but not too much - seems If I maintain 400f flue temps I will not have a stalled cat- work draft down slowly. This process can take much more time than my fireview and I might have to do this cycle a few times on the hybrid.

Last night with stove top at 300f, flue at 500f, I closed the bypass and within a couple minutes there was almost no flame and the flue temps had dropped to 350F, I am almost certain I will find the entry side of the cat plugged with fly ash when I pull it out later tonight. Much more smell in this situation (understandable with plugged cat)

Inside smell - I can smell it in the stove room, and on the second floor in my bedroom. It is not from a backpuff- something I rarely experience with the PH, that is more common on my fireview.
I've been replacing door gaskets on the PH in an attempt to eliminate this smell- no other reason.
No visible leaks - some brown staining on the last gasket I pulled out.

I am sure the cooktop is the unshielded version.
 
The first time I looked at my cat it appeared to be a bit clogged. Since then I've pulled it out about once a month and although I see some ash on it, it doesn't look anywhere near clogged. I generally blow it out (a few deep breaths) outside and will see dust fly out of it then put it back in reversed from the way it was before (the theory being that maybe that will force the dust out the direction it came in... but in any case, no harm in doing it).

Smoke smell - I get that too. I have a new gasket to install whenever I get a good time to do it, but not convinced that it is a door gasket issue as my existing one seems fine to me.

Stovetop temps - I measure just to the side of the flue exit (I vent vertical). Generally my running temps there have been in the 400-500 range with the air just about fully closed (on warmer days I leave it a crack open). I am now running the shielded cooktop and find the temps in the middle are about 120* cooler than the thermometer area (checking with IR gun). The side stones tend to be a bit (20-60*) hotter.

My burn times are legendary for a PH - in a negative sense. Can't explain it, but everything seems 'right' in terms of the way the stove burns and everything but even with the monster splits I can't get an easy reload much after 10-11hrs. Sure there are a few coals in there 12-13 hrs later, but not enough to really load and go. I wonder sometimes about the definitions of the timings that folks report. However, I am getting a lot of heat and overall seem to be burning about the same amount of wood as I did with the FV so I am not complaining. We are doing 3 loads a day now that it is colder out (i.e. temps in the low 30's or less during the day) and that compares to 4-6 a day in the FV (smaller stove after all).
 
My burn times are legendary for a PH - in a negative sense. Can't explain it, but everything seems 'right' in terms of the way the stove burns and everything but even with the monster splits I can't get an easy reload much after 10-11hrs. Sure there are a few coals in there 12-13 hrs later, but not enough to really load and go. I wonder sometimes about the definitions of the timings that folks report. However, I am getting a lot of heat and overall seem to be burning about the same amount of wood as I did with the FV so I am not complaining. We are doing 3 loads a day now that it is colder out (i.e. temps in the low 30's or less during the day) and that compares to 4-6 a day in the FV (smaller stove after all).

Those burn times are pretty much on par for what I see. A full load of 16" splits (oak/honeylocust) at 9pm will be down below 250F by 5am the next morning but lots of coals for a reload- lesser woods perform similar as far as temps but less coals after 8 hrs.... The fireview has a better top temp after 8 hrs but the PH is getting the house warmer. Part of the problem is the short splits, but that's what I have for now.

To be honest I was expecting better burn times but would be satisfied with the stove if my other issues could be resolved.
 
I'm also burning splits that are about 16" - I have another 2 years before those 21" pieces are ready to burn (maybe I'll be lucky and get 3 years... it is oak).

I am hoping to find a solution to the smoke smell, but otherwise I'm very happy with the stove - very much happy about the heat output and ease of running it.
 
Stalled cat after reloads = stove top temp at 250F minimum and the flue drops around 325-350f - I'll go outside and see smoke (not steam) and smell it outside. To solve I reopen bypass for several minutes, get active flames established in the box, close bypass and cut draft but not too much - seems If I maintain 400f flue temps I will not have a stalled cat- work draft down slowly. This process can take much more time than my fireview and I might have to do this cycle a few times on the hybrid.

When you say flue drops to 325-350, do you mean the pipe temp, or some other measurement? When my cat is running, my "flue temp" (measureed with the magnetic temp gauge about 12" above stove on single wall pipe) hovers between 200 and 300, ussually between 225 and 250, and it stays there unless I get a real blazer going with lots of small wood and air turned up. I'm just trying to understand how you are measuring things to compare. My pipe gauge at 200-250 means the flue gasses are 400 to 500 degrees inside (about double outside pipe temp).


Smoke smell - I get that too. I have a new gasket to install whenever I get a good time to do it, but not convinced that it is a door gasket issue as my existing one seems fine to me.

Check that other thread listed above with other possible problems (mising bolt or something...).

Stovetop temps - I measure just to the side of the flue exit (I vent vertical). Generally my running temps there have been in the 400-500 range with the air just about fully closed (on warmer days I leave it a crack open). I am now running the shielded cooktop and find the temps in the middle are about 120* cooler than the thermometer area (checking with IR gun). The side stones tend to be a bit (20-60*) hotter.

That 's about what I see, except my top flue collar only gets up to 400-500 when I'm burning a pretty hot fire, otherwise it's between 325 and 400 normally. But the side top stones are ussually about 20 to 50 degrees hotter than the center stone. And the stone is always 100+ lower than the metal flue collar and cast iron on the rear of stove.


My burn times are legendary for a PH - in a negative sense. Can't explain it, but everything seems 'right' in terms of the way the stove burns and everything but even with the monster splits I can't get an easy reload much after 10-11hrs. Sure there are a few coals in there 12-13 hrs later, but not enough to really load and go. I wonder sometimes about the definitions of the timings that folks report. However, I am getting a lot of heat and overall seem to be burning about the same amount of wood as I did with the FV so I am not complaining. We are doing 3 loads a day now that it is colder out (i.e. temps in the low 30's or less during the day) and that compares to 4-6 a day in the FV (smaller stove after all).

I define "burn time" as the lenght of time from load, to the last time I can re-load without needing to add kindling or a fiewstarter/match... so in otherwords, enough red coals to start new logs. I normally get 10 to 12 hours, wtih what I would call a 1/2 load. That is, I fill the box about 3/4 the way up to top, BUT, the splits are anywhere between 14 and 18" long, so they do not coem anywhere close to reachign the full width of the box, so there is alot of empty space on one, or both sides. Sometimes when I have very short splits, I'll fill that side space in with a small split or two.

When I load with longer splits, 18 to 22", then I get 12 to 16 hours depending on the size of splits, and type of wood. I have noticed the size of the splits makes a BIG difference. Also how you load the splits. If you have smaller splits, you can lenghten the burn time by packing them in tight. If there is alot of airspace betweem them, they will burn much quicker.


Those burn times are pretty much on par for what I see. A full load of 16" splits (oak/honeylocust) at 9pm will be down below 250F by 5am the next morning but lots of coals for a reload- lesser woods perform similar as far as temps but less coals after 8 hrs.... The fireview has a better top temp after 8 hrs but the PH is getting the house warmer. Part of the problem is the short splits, but that's what I have for now.

To be honest I was expecting better burn times but would be satisfied with the stove if my other issues could be resolved.

Something intersting I found last week kinda by accident you guys mith want to try with the shorter splits. Normally I load the short splists in the middle of the box, with 4-6" empty on each side of them. Well, one day I slid them all in not paying attention, and pushed them all all the way back to the other side of the stove. So I ended up with a significant empty space on the door side of the stove, 8 or 10" wide, floor to ceiling. So I took 3 medium to large splits, that were very short (12" or so) and layed them in N-S to fil that empty space. Well, I barely had any red coals on this reload, and somehow the big E-W splits I had pushed all the way in smothered most of the coals out. But the coals under the N-S splits close to the door lit up, and started the N-S splits up. After a few minutes, they got goping pretty good and the stove got up to temp so I closed the bypass and shut down the air, with only 1/4 of the stove burning(the N-S splits), close to the door. Next check of the stove was 12 hours later in the late morning, I had a nice fire still going, not just coals! It seemed as if it burned like a N-S load in a BK or something. It burned from right (door side) to left slowly down the logs. Tmnep in the hosue was normall all night, and the stove was still very hot. It burned for about 4 more hours before I reloaded that day, and I re-loaded on a large hot bed I could have leet go longer.

This could be an actual technique for a long burn, instead of accident. ;)
 
When you say flue drops to 325-350, do you mean the pipe temp, or some other measurement? When my cat is running, my "flue temp" (measureed with the magnetic temp gauge about 12" above stove on single wall pipe) hovers between 200 and 300, ussually between 225 and 250, and it stays there unless I get a real blazer going with lots of small wood and air turned up. I'm just trying to understand how you are measuring things to compare. My pipe gauge at 200-250 means the flue gasses are 400 to 500 degrees inside (about double outside pipe temp).


;)

I am measuring flue temps with a tel-tru probe type thermometer. The sensing coil is inside the probe which is inside the flue pipe. I find them to be fairly accurate. Once the stove is up to temp and cat is working properly, the flue temps will range from 400-500F for the active part of the burn. Most burns are closer to 400F, 500f being an exceptional hot load - smaller splits loaded onto a larger than normal coal bed.
 
Gotcha, that sounds consistent to my temps. ;)
 
Maybe the smoke smell and the burn times are related?

I load and go at 12 hours all the time and often with quite a bit less than a full load. This was from a previous thread and all with 16+/- spilts.....

I think it is mostly split size that causes the difference.

Here were my coals with a 70% (height wise) load after 12 hours. I had just raked them forward.

cimg4081-jpg.85804


Here is a somewhat typical load. This one was a bit bigger than I have been running (maybe 75% height wise) since it was going to be a very windy night. Low of 28.

cimg4082-jpg.85805


This was three big splits, one small split, and one small round. I could have easily fit another big split and two more small splits or rounds. This load will produce coals at least like those shown above after 12 hours. Notice how I stacked two big splits tight on top of each other in the back. Those were 7-8" wide. Also notice I had flame before I finished loading.
 
Have any of you guys measured how much of the firebox is being used with 16" splits? I don't think the burn times being reported are bad for the amount of firebox that is unused.

Also has anyone measured the usable firebox size?

I'd love to see more pictures of these stoves with full loads.
 
Have any of you guys measured how much of the firebox is being used with 16" splits? I don't think the burn times being reported are bad for the amount of firebox that is unused.

Also has anyone measured the usable firebox size?

I'd love to see more pictures of these stoves with full loads.

I have measured it before but now I can't remember the exact dimensions. As I recall, the actual useable space was not too much under the reported firebox size. I think it was around 2.5 cft. I'll take a pic of tonights load although it won't be packed super tight with a low of only 22 degrees and me wanting to reload after 12 hours.
 
However, I did notice there is a slight bend in the top of the frame on it, I took a pic and am sending it to Woodstock to check if ok/normal. But I have yet to see anything get on/in/around the cat or the screen at the top of the firebox. I burn both fully closed for long slow burns sometimes, but mostly with the air slightly open.

Machria;

Was the "slight bend" on the left side of the frame, kind of like it was not completely bolted down properly? Any chance you could post a picture?
 
My cat accumulates ash fairly rapidly. I've wondered if it is my wood (Red Maple, CSS about 20 months with first year outdoors), or if it is a strong draft (tall chimney with insulated liner, house out in the open). Just cleaned the cat during a "warm" day recently, and wife noted that it had only been 2.5 weeks since the last cleaning. It wasn't as bad as I've let it get before, but you could see a clear difference in the flames as the bypass was closed. It probably doesn't help that my screen isn't retaining its shape very well (add heat and it soon sags). We are burning 24/7 (burned 4 full cord to date this season), 18" medium-sized splits.

Regarding smell, we occasionally (rarely) have a slight smell. All gaskets are original. I suspect a clogged cat would accentuate to any smoke leaks.

We aim for higher stovetop temps (500-600), and as a result see a little higher flue temps than you are seeing. Almost always a secondaries burn going in this colder weather.
 
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The new screen doesn't seem to catch much flyash because I rarely have to brush it. This hasn't led to a clogged cat either. I just cleaned mine a week ago for the first time this year and it had a bit of buildup but not bad at all.


Waulie: Has your screen sagged at all? I assume by "new screen" you mean the one that clips into a bracket.
 
Waulie: Has your screen sagged at all? I assume by "new screen" you mean the one that clips into a bracket.

Yeah, it did finally sag. It took a while before it did. I bent it back once and it has since sagged again. It is hanging maybe a half inch in back and I haven't even bothered with it. To be honest, I haven't cleaned the new screen once (other than when I bent it back) since I got it. Therefore, I'm pretty convinced it doesn't really do anything. I mean, if nothing accumulates on the screen, what could it be blocking? I know the draft is designed with the screen in place so I just leave it there but I'm not getting bent out of shape (terrible pun) about it. I just cleaned my cat after a little over 2 cords and had only minor accumulation with no blockage.
 
Also, I didn't take a pic of my load tonight because it was basically identical to the pic above. I'm all set with 12 hour burns and if it's not that cold out, I'm not loading her up full. I'll try to get one when it gets cold again. I should have thought of it the last couple weeks as I had it pretty packed several times.
 
Machria;

Was the "slight bend" on the left side of the frame, kind of like it was not completely bolted down properly? Any chance you could post a picture?

My slight bend is just off center, on the top of it. Kinda like its sagging in one spot. I don't have the pic with me, will post it tomorrow. Woodstock said it was not ok, and is sending a replacement. The cat only had one Verticle support, and they said they normally have two supports, so they are sending me one with 2 supports.
 
Yeah, it did finally sag. It took a while before it did. I bent it back once and it has since sagged again. It is hanging maybe a half inch in back and I haven't even bothered with it. To be honest, I haven't cleaned the new screen once (other than when I bent it back) since I got it. Therefore, I'm pretty convinced it doesn't really do anything. I mean, if nothing accumulates on the screen, what could it be blocking? I know the draft is designed with the screen in place so I just leave it there but I'm not getting bent out of shape (terrible pun) about it. I just cleaned my cat after a little over 2 cords and had only minor accumulation with no blockage.

Whether something is actually stuck on the screen or not does not necessarily depict wether it is blocking anything or not. Don't make that mistake. How much stuff is stuck on your windshield after driving for 10 hours? BUT, just imagine driving 10 hours with no windshield. ;)