FPX or Lopi large hybrid flush cat vs non-cat design

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clydesdale

Member
Mar 8, 2016
150
New York
I have the cat design and it certainly requires maintenance of the cat. I now use a steel cat and it can clog. But, how is the non cat version. Anybody know how the two designs compare. I love the look of these stoves, but does the new one heat well without the cat? Anybody have one? Thanks.
 

icestationzebra

New Member
Mar 29, 2022
7
NY Southern Tier
my FPX was my first experience with a catalytic unit. although I can't quantify it for you, the gains are very tangible to me.

that being said, i'm on my 3rd cat in 8 years of heavy use. they seem to last 3-4 years for me before disintegrating. like everything else, the replacement cost has almost doubled. I think I paid over $400 for the most recent one.
 

clydesdale

Member
Mar 8, 2016
150
New York
Wow, I wish we ran into each other earlier. I am on year 6. I am on my 3rd cat. We burn almost 24/7 from Halloween to present. I am now using a steelcat. I have a brand new ceramic one in the basement in reserves. It was the second one that I got from warranty. I think this insert is beautiful and has many positives, including the glass size, adjustable fan and beauty. I like that FPX can customize the surround to match the arch geometry of the insert and your opening. It looks like it belongs.
But, in my setup, I think the draft brings the flames up to the cat and can degrade it. Another member came up with the idea of a flame deflector and I have used that and I think it helps. The ceramic cats crack and disintegrate in about 2 years for me. The steelcat seems to be holding up much better, but clogs easier. So, I have had to remove it twice this season and spend a 1.5 hrs with a pipe cleaner.
I am wondering if the new version, without the cat, can create the same heat. Thanks.
 

icestationzebra

New Member
Mar 29, 2022
7
NY Southern Tier
as far as cleaning goes, I use a can of compressed air about once a month.... it takes all of about 5 seconds to clean it. I'll also slide the cat out and vacuum 2-3x per season. we burn alot.... about 4-5 cords every season Oct-April. I'm in Orange County NY.

I've refinished/repainted the doors and surround once and they are due again. I've also replaced gaskets twice. This summer I'm going to proactively replace the blower and controls.

I would think it is probably safe to run the fireplace without the cat in it.... just remove it and give it a try. But I would definitely ask an expert before doing that. At the moment i'm running mine without any gasket or insulation material around the cat. It all just fell apart and disintegrated with my last cleaning so there is some open air space around the sides and top of my cat.
 

clydesdale

Member
Mar 8, 2016
150
New York
You can get the interam gaskets from Applied Ceramics in GA or Midwest Hearth. We burn about 8 cords. The oil burner is essentially off. It runs all the time. I don't run it without the cat, but the new model does not use a cat anymore. I am curious if it puts out the same heat. It would be great to eliminate the cat issues.
Most of the cat companies do not want you using compressed air on the cats.
 

icestationzebra

New Member
Mar 29, 2022
7
NY Southern Tier
a couple quick questions for you if you don't mind as you're the first FPX owner i've conversed with that burns as much as I do?

I'm assuming you shut it down at night? Even with very dry wood I wake up to black glass that is a pain the [email protected]@ to clean. From what I read this is common. We use some a caustic chemical spray cleaner that I hate. What is your experience in keeping the glass clean?

Also, are you using a grate? I did for the first few years but gave up replacing them annually and now just burn right on the firebrick floor.

Regarding the compressed air on the cat, I hadn't heard it was bad. My installer and certified FPX retailer that services mine said it was fine to use. I'm going to look into a steel 3rd party cat.

Once I get pricing on the replacement blower and controls i'll post back.

thanks
 

clydesdale

Member
Mar 8, 2016
150
New York
I have marked off my air control with 5 mark lines. At night, I load it and then back it down to 4-4.25. 5 is closed off. When I wake up, I have mostly ash and the window is darker. I usually just reload it at that point and let it back off. When I get home from work, I clean out the ash, sometimes vacuum the cat, and reload. At the point, when it is cold I may also clean the glass before the reload. Don't bother with cleaners. Just grab a paper towel, wet it and then dip it in the ash and use the ash to clean the glass. It is perfectly safe and cleans it beautifully. But, sometimes the glass is still too warm to do this and it just makes a streaking mess. My glass stays fairly clean, but I like to clean it off every 10-14 days.
I do not use a grate. I use the whole box. This is my main source of heat and that would also make cleaning it a real pain in the ass. As it is, I wish it had an ash pan, but realize that won't work in this design.
Check about the compressed air, from what I saw, that was a no no.
 

stoveliker

Minister of Fire
Nov 17, 2019
4,525
Long Island NY
as far as cleaning goes, I use a can of compressed air about once a month.... it takes all of about 5 seconds to clean it. I'll also slide the cat out and vacuum 2-3x per season. we burn alot.... about 4-5 cords every season Oct-April. I'm in Orange County NY.

I've refinished/repainted the doors and surround once and they are due again. I've also replaced gaskets twice. This summer I'm going to proactively replace the blower and controls.

I would think it is probably safe to run the fireplace without the cat in it.... just remove it and give it a try. But I would definitely ask an expert before doing that. At the moment i'm running mine without any gasket or insulation material around the cat. It all just fell apart and disintegrated with my last cleaning so there is some open air space around the sides and top of my cat.
They tell us that any time you take out the cat (different stove), you have to put a new gasket in (it desintegrates every time).
Interam indeed.

We were told indeed that compressed air is a no no - but I've seen other manuals where it is actually suggested for fly ash blockages. If your mfg says it's ok, I'd not worry about it.
The other option is not to blow but to use a vacuum (with a short bristle so you don't rub the hard vacuum cleaner heat against the front edges of the channels inducing crack initiation in the wash coat).

I also second the ash on a wet (paper) towel. My stove gets black too, but I can easily burn it off by running at full air for 30-45 minutes. Some folks use a razor blade (I guess if it's thick, or even goey).

Running without the cat can (in principle) be dangerous; you significantly decrease the air impedance, leading to higher flow. This can make some parts of the stove hotter than normal (see warping, overheating). My stove mfg says not to do this. Period.
Not sure about yours, but if your manual does not explicitly discusses this, I'd be hesitant. IF you do nonetheless, keep an eye on it as the increased flow may result in a larger tendency for runaway. It'll behave somewhat differently.

It also will pump more heat in the flue because of the larger flow. So it's inefficient.
 
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webby3650

Master of Fire
Sep 2, 2008
11,121
Indiana
a couple quick questions for you if you don't mind as you're the first FPX owner i've conversed with that burns as much as I do?

I'm assuming you shut it down at night? Even with very dry wood I wake up to black glass that is a pain the [email protected]@ to clean. From what I read this is common. We use some a caustic chemical spray cleaner that I hate. What is your experience in keeping the glass clean?

Also, are you using a grate? I did for the first few years but gave up replacing them annually and now just burn right on the firebrick floor.

Regarding the compressed air on the cat, I hadn't heard it was bad. My installer and certified FPX retailer that services mine said it was fine to use. I'm going to look into a steel 3rd party cat.

Once I get pricing on the replacement blower and controls i'll post back.

thanks
I think you must have an FPX 44 or 36 Elite, the OP is talking about fireplace inserts. The elite models don’t do well at all when the air control is reduced below half. The insert is a hybrid, so it’s not as restricted and doesn’t get the same build up on the glass.
 
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FPX Dude

Feeling the Heat
Oct 4, 2007
417
Sacramento, CA
if it helps, I use no grate, have steel cat, brush it in place once a week for any ash, I dunno but like 6+ years or more, still glows red at 650 and blasts out the heat. Probably has a lot to do with wood you're burning too. I take out every year and blow with compressor, then put back with new gasket, that's it.
 
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