My not so great experience with FPX catalyst insert - Advice?

Dmitry

Minister of Fire
Oct 4, 2014
784
CT
Not discouraged. I do like the heat output - it's incredible - and enjoy the beauty of the fires, especially when the combuster is engaged. Looks amazing. Just think for the price point, there should be zero issues. Having to make modifications to the design, although genius on your part, isn't something I expected. Now, so far so good for me. Cat seems to be working as advertised, no problem. Hopefully that continues, o/w I'm going to do what you did with the steel plate, although I'm leery. Is it working out for you?
Also, the glass on my unit gets real black every night. Haven't had any success burning it off with real hot fires. I like the glass clean and have been using a baking soda paste that works great, but wonder what your experience has been in this regard. I understand that as the fire burns out the glass can get dirty. Don't mind cleaning it, but wonder if there's any tricks to keeping it clean.
Happy New Year!
Davo covered it pretty much. Mu cause of dirty glass was closing air too soon and subpar wood. You have 22% wood and it's not ideal but I understand there is no choice. Try to play with closing air later in burn. Your time will vary because everyone has different setup. Yeah, and don't expect flames going on for 5 hours, lot of hot coals keeping stove warm and cat working and it counts toward so called" burn " time.
 

Ashful

Minister of Fire
Mar 7, 2012
14,745
Philadelphia
Exactly my set up and reason for not having cat probe.
If everything is working well for you guys without one, that’s great. But I think it’s going to be awful difficult to determine the cause of troubles for those having issues, without one.
 

FPX Dude

Feeling the Heat
Oct 4, 2007
297
Sacramento, CA
If everything is working well for you guys without one, that’s great. But I think it’s going to be awful difficult to determine the cause of troubles for those having issues, without one.
I don't have one either, I suspect many people don't. On reload, I keep the door cracked and leave bypass open a few inches. Then, after a few minutes the door starts bumping a few millimeters or so, against the frame to remind me that the draft is pulling pretty hard (I can hear it too), so I close the door, then another ~5mins. and I can't see a faint orange starting on the CAT, close the bypass, boom solid orange, and throttle the air to cruise control.
 

Tegbert

Feeling the Heat
Sep 15, 2016
397
Arlington Wa
I don't have one either, I suspect many people don't. On reload, I keep the door cracked and leave bypass open a few inches. Then, after a few minutes the door starts bumping a few millimeters or so, against the frame to remind me that the draft is pulling pretty hard (I can hear it too), so I close the door, then another ~5mins. and I can't see a faint orange starting on the CAT, close the bypass, boom solid orange, and throttle the air to cruise control.
I have a cat probe on my rockport and I have done that a few times. Usually when mine does that the cat temp is well over 500 sometimes pushing 650 or so.


Lopi Rockport
Blaze King Ashford 25
 

joewasilla28

New Member
Oct 26, 2018
14
Norwich, New York
Lots of great posts-thanks! For my overnight burns I haven't been pulling the coals forward like you all are saying, so I'm gonna do that tonight. Today I loaded the box tighter and fuller and noticed a much longer burn time - just by putting 2 extra pieces in. Like I've mentioned, I'm trying to stretch the wood I have that was left by the previous homeowners, so haven't really been packing the firebox full. I'm also learning that like Dmitry says, burn time doesn't mean visible flame time! This morning my glass was pretty much smoked out (like almost all mornings) but today I just kept the fire going without concerning myself with cleaning it. We love to watch the fire, but this morning I loaded her up and got her burning good, engaged the cat at around 550, and closed the air all the way down, and it burned great all day....just kept pumping out the heat! Couldn't see a thing, but she sure was hot! Normally I'd just shut the air 1/2 way cause I wasn't sure the fire would keep burning. So far the cat in this FPX has been terrific. The wife and I have already been pulling wood out of the forest behind the house for next year, and beyond. It's great exercise and there's a seemingly endless supply.
 

jatoxico

Minister of Fire
Aug 8, 2011
4,067
Long Island NY
This morning my glass was pretty much smoked out (like almost all mornings) but today I just kept the fire going without concerning myself with cleaning it.
If you have fireproof or even leather gloves you can wipe the glass with newspaper while hot and get a lot of fly ash and haze off. Won't take off the baked on blackness but usually can improve things.
 

weatherguy

Minister of Fire
Feb 20, 2009
5,330
Central Mass
Are you guys cutting the air back at 600 degrees or so? The dealer nd manufacturer told me to get it up past 1000 then cut the air back.
Stove top temp is half the firebox temp, he probably means 500 stove top.
 

Ashful

Minister of Fire
Mar 7, 2012
14,745
Philadelphia
Are you guys cutting the air back at 600 degrees or so? The dealer nd manufacturer told me to get it up past 1000 then cut the air back.
As soon as I hear "cut back at xxx degrees", I assume they're only experienced with running non-cat stoves. Besides, as weatherguy alluded, 600 degrees where?

If you're running a cat stove or insert, the only thing you really ever need to watch is the cat probe thermometer. A chimney probe thermometer is also helpful, for knowing when the stove is ready to engage the cat, but that's about it.

My Jotul Firelight 12 cat stove operating procedure:

1. Light fire, and run with bypass open until chimney probe reaches 600F.
2. Close bypass, and wait for combustor probe temp to hit 750F.
3. Reduce air to 50%, set timer for 5 minutes.
4. Reduce air to 25%, set timer for another 5 minutes.
5. Reduce air to final operating point.
6. Come back to reload on coals in 10 - 20 hours, depending on chosen operating point.

My Blaze King 30 cat stove operating procedure:

1. Light fire, and run with bypass open until cat probe reaches 500F or chimney probe reaches 600F, whichever happens first.
2. Cose bypass, and run stove on high for 20 minutes.
3. Verify combustor is > 1000F (it always is, unless my wood was wet), and turn air down to final operating point.
4. Come back to reload on coals in 12 - 36 hours, depending on chosen operating point.

Pretty simple.
 

Tegbert

Feeling the Heat
Sep 15, 2016
397
Arlington Wa
Are you guys cutting the air back at 600 degrees or so? The dealer nd manufacturer told me to get it up past 1000 then cut the air back.
Once I hit 500 on the cat probe I close the bypass. Then about 20 min later I shut it down to low. Unless the flue probe gets too hot then I’ll cut the air in increments depending on how charred the wood is or shut it to low. Once the bypass is closed I don’t even bother with the cat probe anymore.


Lopi Rockport
Blaze King Ashford 25
 

Carlv123

Member
Feb 17, 2015
96
Asheville nc
Update: Installer came out and the damper wouldn't fit so he decided to block 2/3 of the vent at the chimney cap. It did help and this week with the extreme cold will be the tell tale sign.

He did say that the clay chimney was 11x11 so I had a thought. Since the ideal height is 15 ft, what if I had the 6" liner for the first 12-15' then opened it up to a 10" pipe? It would be like the older installs but still have a full liner.

Any thoughts on this?
 

edyit

Minister of Fire
Nov 30, 2014
815
Wilmington NY
Since the ideal height is 15 ft, what if I had the 6" liner for the first 12-15' then opened it up to a 10" pipe? It would be like the older installs but still have a full liner.

Any thoughts on this?
that doesn't sound like a good idea to me, the top of the chimney is usually where it is coolest, going from 6" to 10" is going to slow it down and cool it even more. sounds like a creosote making machine.
 

Carlv123

Member
Feb 17, 2015
96
Asheville nc
that doesn't sound like a good idea to me, the top of the chimney is usually where it is coolest, going from 6" to 10" is going to slow it down and cool it even more. sounds like a creosote making machine.
The whole point is to slow the draft down. Right now it's too much and this is the only solution.
 

Ashful

Minister of Fire
Mar 7, 2012
14,745
Philadelphia
The whole point is to slow the draft down. Right now it's too much and this is the only solution.
Keep in mind that a single restriction in a 6” pipe, like closing off the top or a key damper, may result in substantial smoke spillage when you open the door to load. You need the volume of a 6” pipe to keep that door opening drafting the right direction. This is why a key damper works so nicely, open it when you’re loading, close it when you’re running.
 

jatoxico

Minister of Fire
Aug 8, 2011
4,067
Long Island NY
Not to mention how do you sweep a setup like that? Anything swept from the larger liner can fall outside the 6" . If it lands in the firebox you have to pull the unit to clean if it gets trapped and accumulates in the flue it can light off.
 

Carlv123

Member
Feb 17, 2015
96
Asheville nc
Not to mention how do you sweep a setup like that? Anything swept from the larger liner can fall outside the 6" . If it lands in the firebox you have to pull the unit to clean if it gets trapped and accumulates in the flue it can light off.
I would use a reducer to go from the 10" to 6" so it would still be continuous. I'm getting such a draft I need to reduce it and there's no way to install a key damper.
 

Dmitry

Minister of Fire
Oct 4, 2014
784
CT
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Laker616

New Member
Feb 14, 2019
1
WI
I'm so glad that I stumbled upon this forum and specifically this thread. I installed a large flush hybrid in Oct, 2018. I too have been disappointed in the burn times. Having to load every 3-4hrs, lucky if I get a 6hr burn. The wood I'm burning is anywhere from 12-16% MC and it's mostly oak and hickory. My chimney is 15ft high. This was a demo model that the dealer gave me a hell of a deal on (their words). Now it's gotten to be where I have to leave the bypass open even a little bit or the fire goes way down. My temp at the CAT says 600-800 when I close the bypass and goes down to under 500 and looks like it's going out. I too am looking for tips on how to get those long burn times. My house is older so I know the are issues with that. I can load the fire box and cant get temp in room up over 70 most days.
 

webby3650

Master of Fire
Sep 2, 2008
10,189
Indiana
I'm so glad that I stumbled upon this forum and specifically this thread. I installed a large flush hybrid in Oct, 2018. I too have been disappointed in the burn times. Having to load every 3-4hrs, lucky if I get a 6hr burn. The wood I'm burning is anywhere from 12-16% MC and it's mostly oak and hickory. My chimney is 15ft high. This was a demo model that the dealer gave me a hell of a deal on (their words). Now it's gotten to be where I have to leave the bypass open even a little bit or the fire goes way down. My temp at the CAT says 600-800 when I close the bypass and goes down to under 500 and looks like it's going out. I too am looking for tips on how to get those long burn times. My house is older so I know the are issues with that. I can load the fire box and cant get temp in room up over 70 most days.
Sounds like you cat is partially clogged with ash. Have you brushed and vacuumed it out?
 

Ashful

Minister of Fire
Mar 7, 2012
14,745
Philadelphia
The wood I'm burning is anywhere from 12-16% MC and it's mostly oak and hickory.
It's mighty tough to get oak down to 16% in Wisconsin, let alone 12%. Can you describe your measurement process? If it's not 3 places on a freshly-split face at 70F, your readings are likely off. Cold wood will always read low, and frozen wood will read crazy low. An old split face will also always read low.
 
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Dmitry

Minister of Fire
Oct 4, 2014
784
CT
I'm so glad that I stumbled upon this forum and specifically this thread. I installed a large flush hybrid in Oct, 2018. I too have been disappointed in the burn times. Having to load every 3-4hrs, lucky if I get a 6hr burn. The wood I'm burning is anywhere from 12-16% MC and it's mostly oak and hickory. My chimney is 15ft high. This was a demo model that the dealer gave me a hell of a deal on (their words). Now it's gotten to be where I have to leave the bypass open even a little bit or the fire goes way down. My temp at the CAT says 600-800 when I close the bypass and goes down to under 500 and looks like it's going out. I too am looking for tips on how to get those long burn times. My house is older so I know the are issues with that. I can load the fire box and cant get temp in room up over 70 most days.
Something is wrong. I second on clogged cat. My wood is not near 20% and there is no oak. If I put 16 % Oak , I would cook my wife out of the house in an hour. and its 2000sq ft house in CT