questions about possible repairs for a Vermont Castings Defiant

[cjung]

Hi,
We have a Vermont Castings Defiant Encore (catalytic) wood stove in our basement apartment. It was installed by a previous home owner around 1998. Our tenants started to use it earlier this month and were having trouble with getting good fires. I tested it and noticed that the fire seemed starved for air and so yesterday I thoroughly cleaned and vacuumed the stove and checked the primary air intake (I think I sucked out some ash from it). Last night's fire performed better but I'm keeping my eye on this. I've told the tenants to clean out the ash more often.

While I was at it, I decided to check the catalytic unit. Two years ago, I had the wood stove checked by one of our local wood stove installers, in particular I was concerned about a section of the refractory material to the right of the catalytic element that was missing. He said it was no big deal and not to worry about it. Well looking at it again, I'm not so sure and want to get a second opinion.

I've attached the following photos:
- The missing refractory material which leaves most of the right side of the catalytic unit exposed
- bubbled paint that looks to be the result of heat from the right side of the catalytic cover. This concerns me a lot!
- the left side of the catalytic unit showing the refractory material whole and in place and to show that there's no bubbling of paint on that side.

In addition, I also noticed that the gasket material is totally flat and I wonder if it's making a good seal. I see some of the gasket fibers are stuck to the stove.

Here's my questions:

Is the bubbled paint due to the missing refractory material or the gasket not making a good seal or a combination of both?

What's the safety implications? I love my tenants and don't want to kill them!

Would the missing refractory material affect the performance of the catalytic process?

My manual does have some instructions for replacing the gasketing. Is this a job that I, as a cautious DIY-er, can do? (by cautious I mean that I'm so concerned about safety that I've been know to over engineer projects & repairs)

Can the missing refractory material be replaced or patched? It seems pretty fragile and easy to break so I wonder if trying to repair it might result in breaking it apart even more. Does anyone know if the whole refractory lining be replaced as a unit?

Thanks for any help or advice!

LC

 

[redhat]

It appears from your photos that the top of the refractory box is also missing, but can't tell for sure from the photo. Is there refractory material above the catalytic converter? Also, do you have the refractory access cover that sits between the cat and the cast iron access panel?

 

[grommal]

Hi,
We have a Vermont Castings Defiant Encore (catalytic) wood stove in our basement apartment. It was installed by a previous home owner around 1998. Our tenants started to use it earlier this month and were having trouble with getting good fires. I tested it and noticed that the fire seemed starved for air and so yesterday I thoroughly cleaned and vacuumed the stove and checked the primary air intake (I think I sucked out some ash from it). Last night's fire performed better but I'm keeping my eye on this. I've told the tenants to clean out the ash more often.

While I was at it, I decided to check the catalytic unit. Two years ago, I had the wood stove checked by one of our local wood stove installers, in particular I was concerned about a section of the refractory material to the right of the catalytic element that was missing. He said it was no big deal and not to worry about it. Well looking at it again, I'm not so sure and want to get a second opinion.

I've attached the following photos:
- The missing refractory material which leaves most of the right side of the catalytic unit exposed
- bubbled paint that looks to be the result of heat from the right side of the catalytic cover. This concerns me a lot!
- the left side of the catalytic unit showing the refractory material whole and in place and to show that there's no bubbling of paint on that side.

In addition, I also noticed that the gasket material is totally flat and I wonder if it's making a good seal. I see some of the gasket fibers are stuck to the stove.

Here's my questions:

Is the bubbled paint due to the missing refractory material or the gasket not making a good seal or a combination of both?

What's the safety implications? I love my tenants and don't want to kill them!

Would the missing refractory material affect the performance of the catalytic process?

My manual does have some instructions for replacing the gasketing. Is this a job that I, as a cautious DIY-er, can do? (by cautious I mean that I'm so concerned about safety that I've been know to over engineer projects & repairs)

Can the missing refractory material be replaced or patched? It seems pretty fragile and easy to break so I wonder if trying to repair it might result in breaking it apart even more. Does anyone know if the whole refractory lining be replaced as a unit?

Thanks for any help or advice!

LC

I used a Defiant Encore for 23 years. Does the fire seem starved for air only when the bypass damper is closed? If so, is this true even when the primary air control is open all the way? If that's the case, then the refractory in the area below the catalyst may be crumbling and blocking the flow.

If you're missing a significant chunk of the cat honeycomb, it should be replaced. It's easy to overfire this stove (when the airflow is not restricted!) and really shorten the life of the cat. Are the burns being monitored by a thermometer on the top of the stove?

 

[cjung]

Thanks for the replies. I took my photos to the local Vermont Castings dealer who determined that the whole refractory box needs to be replaced to the tune of $500-600. He also suggested replacing all the gaskets, not just the one to the catalytic unit. We had replaced the catalytic element two years ago (ouch) and it still looks fine.

This wood stove has always been a temperamental thing and it's hard to get it to burn efficiently (takes a lot of baby sitting to get into the catalytic after burner mode). With that in mind and the repair bill plus the tax credit incentive, we are thinking of replacing instead of fixing it. I think I'll start a new thread with questions regarding that search.

Thanks again.

 

[cjung]

It appears from your photos that the top of the refractory box is also missing, but can't tell for sure from the photo. Is there refractory material above the catalytic converter? Also, do you have the refractory access cover that sits between the cat and the cast iron access panel?

Good eye - the refractory material above the catalytic unit is missing. We do have the access cover and it's sound.

 

[SolarAndWood]

I made that same decision recently. Have you considered just removing it? That is even better than the tax credit and you have one less thing to maintain as a landlord.

 

[grommal]

Thanks for the replies. I took my photos to the local Vermont Castings dealer who determined that the whole refractory box needs to be replaced to the tune of $500-600. He also suggested replacing all the gaskets, not just the one to the catalytic unit. We had replaced the catalytic element two years ago (ouch) and it still looks fine.

This wood stove has always been a temperamental thing and it's hard to get it to burn efficiently (takes a lot of baby sitting to get into the catalytic after burner mode). With that in mind and the repair bill plus the tax credit incentive, we are thinking of replacing instead of fixing it. I think I'll start a new thread with questions regarding that search.

Thanks again.

I also had a love/hate relationship with our old VC. Very touchy, very prone to backpuffing, hard to walk the line between overfiring and smoldering. Our new Oslo is an entirely different animal. We've only had about 8 days of burning with it so far (a few in the spring right after installation, and a few in the last week), but it has already impressed me with the way it just perks happily along.