Can I burn without CAT gasket for 2 weeks?

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Poulet01

Member
Dec 16, 2020
8
Laval, Québec
Hello,

I have a hearthstone heritage 8024. I had recently been having huge backpuffing problems when I engaged the bypass handle. I thought it was the cat that was clogged, so I cleaned it, and the backpuffing stopped. The thing is, the gasket around the cat was worned out and most of it fell out when I cleaned it. There is no store near me that sells it, so I will have to order new ones, but it will be at least 2 weeks until I receive them.

So my question is: what happens if you run a cat stove with little to no gasket around the cats?
 
This could be the wood. If it is not fully seasoned to the core, the fire can die out and start to smolder. When a flame appears it ignites the accumulated smoke.

To get the gasket quickly buy it from a place that sells it by the foot. Search for Interam gasket. If you have an Amazon account that may be faster?

Amazon product ASIN B084T8SD4R
or
 
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Thank you for the reply, I will get the interam by saturday!

In the meantime, do I risk dammage to the cat if I burn with little to no gaskets around them?
 
Thank you for the reply, I will get the interam by saturday!

In the meantime, do I risk dammage to the cat if I burn with little to no gaskets around them?
Yes, possibly. It's a good idea to have spare gasket material on hand as well as an extra cat in case something goes wrong with it.
 
Yes, possibly. It's a good idea to have spare gasket material on hand as well as an extra cat in case something goes wrong with it.
I have another question concerning my heritage 8024. According to the manual, there should be 2 baffles in the stove, a front one and a rear one. There is only one in mine, I will attach a photo. It goes from the rear air tube to the front air tube.

Now the thing is, the first year my chimney got swept after I got the stove, the sweeper accidentally broke the baffle, so they bought me a new one. At the time, I didn't even bother to look at what they used to replace it. Did they give me the wrong part or is this just the same baffle but in one big piece instead of 2?
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About how old is your stove? I believe the pre-2020 stoves may have had a single baffle. My stove is about 2 years old and it has the split baffle, a smaller one in back and then a larger in front (which is held in place with a clip to the front burn tube).
 
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About how old is your stove? I believe the pre-2020 stoves may have had a single baffle. My stove is about 2 years old and it has the split baffle, a smaller one in back and then a larger in front (which is held in place with a clip to the front burn tube).
The stove was made in 2020. The more I think about it, the more I believe there was 2 small baffles when I bought it. The sweepers must have replaced it with a single big one because it was more easy to find or cheap. If you could please tell me the width of both your baffles, I could compare to mine. If it's about the same width, I don't think it makes a big difference.
 
Back-puffing is generally caused by a inconsistent cycling of O2 / woodgas ratio in a hot firebox. This can be caused by trying to burn too low and slow for the amount of draft provided (i.e. chimney height) or bad stove design. If you search the forums and don't find a lot of reports of backpuffing in this stove, then I'd assume the former, and try not turning down so far.

It can also be caused (temporarily) by turning the stove down too quickly. If this is your case, you can resolve it by turning down in a few small increments spaced at least 5 - 10 minutes apart.
 
Back-puffing is generally caused by a inconsistent cycling of O2 / woodgas ratio in a hot firebox. This can be caused by trying to burn too low and slow for the amount of draft provided (i.e. chimney height) or bad stove design. If you search the forums and don't find a lot of reports of backpuffing in this stove, then I'd assume the former, and try not turning down so far.

It can also be caused (temporarily) by turning the stove down too quickly. If this is your case, you can resolve it by turning down in a few small increments spaced at least 5 - 10 minutes apart.
If the catalytic converter is clogged, then the draft will be reduced, no? I seriously think that was the problem. Since I cleaned it, the problem went away. It's been 2 days now and the stove is burning slow and hot with the cat engaged, and no signs of backpuffing.

The thing is, since the cat gasket is almost entirely gone, I think there is too much draft now, since air can pass on the sides of the cat. When the gasket was still there, the flames reduced a lot when I engaged the cat. Now, I barely see a difference. I have to reduce the air intake a lot or the wood is burning faster than usual. I will get the new gaskets saturday, so I will be able to test and see. In the meantime, I don't load the stove too much and I check the catalyst probe to make sure it doesn't overheat. It seems fine.
 
Yes, if the cat was clogged, it could cause this problem. My older stoves (Firelight 12's) had a combustor of too little cross-section for the size of the firebox, and it was also prone to this problem.

But you don't have too much draft due to lack of gasket, as draft is completely controlled by chimney height and air inlet setting. Your flame should not die down when you close the bypass damper, there should be very minimal change. On a properly tuned system with ~.05"WC draft, the change in chimney pressure due to closing the bypass is only around 10%. In fact, the way I know it's time to clean my cat is when closing the bypass causes a change of more than .01"WC (20% on .05"WC nominal), when closing the bypass.

Put otherwise, if you're seeing flame die down when closing the bypass, something is amiss. Are you sure you don't have too much chimney, and it's compensating for wet wood when in bypass? If you have too much draft, then yes... closing the bypass would make a more noticeable difference in net draft.

And on running without the gasket, it is probably fine to do on a temporary basis. My concern is that without constraining the can on the cat, any interam gasket wrapped around the ceramic cells will cause the outer steel can to bulge and distort. After this, you could have trouble getting it back into position with fresh gasket.