Defiant Encore Model 2190 Stove

Repair Replacing the Catalytic Firebox HOWTO

Brian Mork © 2013

This page describes procedures to replace the catalytic convertor box of an Encore model stove. It appears other stove models are similar enough to benefit from these instructions; see also resources at the bottom of the page. Usually, a catalytic converter (the ceramic honeycomb with a metal frame) gets cracked, damaged, or clogged. That's reasonably easy to replace by pulling forward the fireback and the little ceramic catalytic convertor box access hatch. In contrast, this web page describes how to replace the entire catalytic convertor box, which encloses the catalytic converter. Click on any picture to see a close-up view.

Picture #1 - This shows the two front log blocking posts, the metal wedges on left and right side, the fireback is in place, the two side panels are in place and the rod-hanging pivot scoop is in place. In the shadows at the inside top of the stove is the flue where the hot flames go in non-catalytic mode.

First step is to remove the two posts that block logs from falling against the front glass windows. I used an 11 mm socket, but I think the bolts are intended to be 7/16” (7/16” is 0.1/16” larger than 11 mm). You just have to loosen the bolts and then the posts slide upward to come out.

Picture #2 – This shows the side plate that must be removed to take out the heavy metal flue flapper box. Bottom bolt is visible in the shadow of the log post. The top bolt is not visible in this picture, hiding behind the red upper lip of the door. 7/16” or 11 mm socket will, although I used an 11 mm socket.

Picture #3 – This shows the two bolts that have to be removed to take out the right side (as looking at the stove) side plate. It may be possible to not remove this plate and still change the catalytic box, but clearances may not be enough The bottom bolt is visible just above the red bottom lip of the door frame. The top bolt is ½ visible just under the curved red door frame. 7/16” bolt.

Picture #4 - Look in the back of the stove and lightly tap upward on the two metal wedges on the left and right side. Once they are loose and removed, the fireback will freely tilt forward toward you. Remove. The picture above shows the normally non-visible back side of the fireback plate.

Picture #5 - This shows the left side looking into the stove where the heavy metal flue flapper box was attached. One bolt per side. The fit is very awkward. See two horizontal slider protrusions. The flapper box has to be fit onto these and pressed against the back wall of the stove, plus it's very heavy. Re-installing this piece probably requires 2 people. Look carefully to see the bolt hole through which the 7/16” (11 mm) bolt is removed from the back exterior of the stove. See also the angular arm that connects the flue flappy handle to the flue flapper. Once you disconnect this arm, the heavy metal flapper will have a tendency to rotate down and pinch fingers or hit the catalytic box.

Picture #6 - This shows the right side looking into the stove. You can see the flat flange that the flapper box fits against and the bolt hole through which the 7/16 (11 mm) bolt fits from the outside of the stove. When removing the heavy metal flapper box, the right side will come loose and lower first. Rotate it down and toward you as you squat in front of the stove. Then the left side will pull away from the interior of the stove.

Picture #7 - This is the left side of the flue flapper box – by far the most difficult to remove and replace part of the job. See the two molded iron protrusions? They have to fit into grooves molded into the stove itself.

Picture #8 - After you remove the heavy flue flapper box, you will be able to freely lift out the catalytic converter box. Wait! Before you try to remove the box, unscrew the stainless steel panel on the back of the stove and remove the auto-damper and the mounting screw for the temperature spring. Gently pull the temperature spring and the temperature probe straight out the back. When re-installing the new flew box, use a drill and handle-wiggle a hole through the mounted catalytic box to receive the temperature probe.

Picture #9 - The catalytic converter access panel is designed to allow easy replacement of the catalytic convertor. The silver catalytic converter shown in this picture is fine, even after 15 years. To get a long life, be sure to start fires directly up the chimney (flapper open) until the stove is hot and the logs are "burning clean".  When adding new logs, open the flapper until the loose stuff is burned away.

I slide the catalytic converter out and slid it into place in the new flew box.

Picture #10 - This is what the back of the stove looks like after you removed the catalytic box. The little slot in the back is the auto-damper where fresh air can come in under the box for combustion. Be sure to clear out all ash from all areas around the box, and out of the groove that the fireback plate will drop back into. Uhh.. yea.. I didn't clean out all the ashes and charcoal; I sort of just swept it into a pile in the middle. It would be better if you cleaned this all out before even starting the project.

Picture #11 - Overall project view when ½ done (taken apart).

Picture #12 - In this picture, the new catalytic box has been replaced, the heavy flue flapper box has been replaced, and the firebox back has been set into place and is tilting forward. When the two side panels are replaced (two bolts each), then the wedges will be used to hold the fireback firmly against the new catalytic box. The rod-hanging air scoop has not yet been replaced. I found that sliding the left hinge in first, and then sliding the entire assembly to the right lets the hanging bars engage properly.

Picture #13 - Lastly, don't forget to put the temperature probe back in the the back of the stove. I used a small drill and rotated it with my finger to gently make a hole in the new catalytic box for the temperature probe.

These photos document the second time I took apart the stove to access the converter box.  I also have photos from the first time, which used to be available on facebook.  If you're interested, let me know.

Update September 2011:  Correspondence with SteveP while he replaced parts of his stove yielded a few pictures and a service manual for what appears to be a slightly older model of the stove:


Picture #14  This picture is toward the interior upper left side.  On my stove, the entire left wall has a plate bolted to it.  This 1986 model stove seems to have just a dog-ear piece up top, holding the flue damper box in place.


Picture #15 - The fireback wall on mine is held in place with wedges.  His appears to be held in place with two bolts on either side, and two more bolts holding the air scoop in place for the catalytic converter.


Click the image to download the pdf for the 1986 model stove.

Update December 2011:  Correspondence with DavidK provided an instruction booklet about how to replace the fireback iron plate on an Encore 2550 stove.   In reality, the booket also includes instructions for replacing the catalytic converter box behind the iron fireback:

cover page image

Update January 2014: DougH wrote, "We thought we should mention that we needed to tap the damper box quite a bit with a rubber mallet  to release it from the back of the stove, it appeared to be glued or rusted stuck and a bit difficult to loosen.  Got those instructions from a dealer we called when we could not get it free once the bolts were out.  He warned us not to be too aggressive as it is cast and we could risk cracking the damper box and would need to replace it if that happened.

Also, we found the Combuster box at Stove parts Unlimited on line for a significant discount from a dealer or any other place online we found.  Said it would take 2-4 weeks to special  order but was here within just over a week.

Thanks again for taking the time to do the web info as there were no other instructions that came with the part.  We found it very helpful!"  

© 2013 Brian MorkPlease contact me using the copyright link prior to commercial use, or reproducing for distribution in a commercial context.