Defiant Encore crack in fireback

[muir mackean]

My mid-90s Defiant Encore has developed a crack & bulge in the fireback, which is pushing the combustion throat (I think that's the correct term, the plate that hangs on two ledges in front of the upper fireback) forward and causing it to fall off its ledges at the slightest provocation (a touch from a log). I hope my photos show the problem (taken with the combustion throat removed).
Questions:
- is this normal, or the result of over-heating? I'm not aware of having run the fire too hot.
- can you get a new fireback, or repair the existing one in any way? If I could grind back the bulge that would make a big difference.
Thanks in advance for any suggestions.

 

[Fsappo]

I remember replacing dozens of encore firebacks back in the day. You can try Cozy Cabin for parts, search them online. If I saw a picture of the whole back of the stove (inside back) I may be able to recall what was involved. It was about 20 years ago last time I did one.

 

[homebrewz]

I had to replace mine in my late 80's Defiant Encore, but the stove was repeatedly over-fired by the previous owner. If you are not the original owner, perhaps this is the case.

Both fire-backs should unbolt from the interior of the stove and there will probably be gasket material which seals it to the stove. You may find the shipping cost on cast iron parts to be prohibitive. If you have a local shop that does regular orders on these parts it might be a better deal. Make sure the damper isn't warped too, or it might not align with the new firebacks.