Hi. Need some help here fellas. Been burning my 1986 VC Defiant Encore Cat Model 28 for a few years now very successfully. Did a partial rebuild this summer mainly to replace a damper tab. Did the cat while I had the stove pulled out as well as all backside gaskets. Inspected thermostat coil but opted not to replace as intake was fully open with cold stove and there were no signs of damage, I now question this decision.
Anyhow, as you probably know, when you put the back of the stove back on, the top and side are sealed with fiberglass gasket but the bottom has no rope, just gets cement. I sealed it with another tube of 2000 degree gasket cement. Put it all back together and did a cure burn to 500 degrees. no problems. A couple weeks in and 6-7 early season fires, I'm on the couch with my girl watching the Bruins game and the stove starts to fire up. Everything was on cruise control in cat mode at 450-500 exhaust baffle temp. Temp shoots up to 700 and I can see thru the box and into the exhaust outlet, looks like the refractory area is glowing red.....i cut off the air and am able to bring the stove slowly down and let it burn out the night with the lever/intake closed, an action that would normally snuff out the stove to the death.
I suspected the cement seal had given way allowing air to scream in. In retrospect, I am unsure. I pulled out the stove, pulled the back off again, cleaned out the old cement, and put it back in with a very healthy serving of Rutland black furnace cement via putty knife. I chose this after calling Rutland for their advice on which sealant would be best. Let it set up in place for 3-4 hours, put it back to the pipe and did another cure burn. Inspection yielded no other cracks or problems. All good. Until last night. Had a few nights normal burning and then last night, same failure, same temps shooting high, same visual of glowing red thru the exhaust as if Hell resided in the refractory system. Note that my refractory system has many cracks and some pieces of the ceramic have fallen apart. But this would not explain fresh air.
So Help me out before I rip it apart again.....My thoughts are: 1-Possible same gasket failure although I don't see how this could possibly be the case. 2-Some sort of refractory failure I am unfamiliar with but if so, how is the fresh getting in to fuel up the fire, did I mention I can hear it roar in? Or, 3-Could this possibly be a thermostat issue that is randomly opening the intake on a warm stove with even fire? Would this cause it to roar? 4-Something else????
What do you think...it's getting colder, times are tough, and I need this old baby to work for me. Thanks!
Anyhow, as you probably know, when you put the back of the stove back on, the top and side are sealed with fiberglass gasket but the bottom has no rope, just gets cement. I sealed it with another tube of 2000 degree gasket cement. Put it all back together and did a cure burn to 500 degrees. no problems. A couple weeks in and 6-7 early season fires, I'm on the couch with my girl watching the Bruins game and the stove starts to fire up. Everything was on cruise control in cat mode at 450-500 exhaust baffle temp. Temp shoots up to 700 and I can see thru the box and into the exhaust outlet, looks like the refractory area is glowing red.....i cut off the air and am able to bring the stove slowly down and let it burn out the night with the lever/intake closed, an action that would normally snuff out the stove to the death.
I suspected the cement seal had given way allowing air to scream in. In retrospect, I am unsure. I pulled out the stove, pulled the back off again, cleaned out the old cement, and put it back in with a very healthy serving of Rutland black furnace cement via putty knife. I chose this after calling Rutland for their advice on which sealant would be best. Let it set up in place for 3-4 hours, put it back to the pipe and did another cure burn. Inspection yielded no other cracks or problems. All good. Until last night. Had a few nights normal burning and then last night, same failure, same temps shooting high, same visual of glowing red thru the exhaust as if Hell resided in the refractory system. Note that my refractory system has many cracks and some pieces of the ceramic have fallen apart. But this would not explain fresh air.
So Help me out before I rip it apart again.....My thoughts are: 1-Possible same gasket failure although I don't see how this could possibly be the case. 2-Some sort of refractory failure I am unfamiliar with but if so, how is the fresh getting in to fuel up the fire, did I mention I can hear it roar in? Or, 3-Could this possibly be a thermostat issue that is randomly opening the intake on a warm stove with even fire? Would this cause it to roar? 4-Something else????
What do you think...it's getting colder, times are tough, and I need this old baby to work for me. Thanks!
I bought my #0028 not knowing much about stoves and just based on the good reputation of the older VC's. I didn't pay very much for it, but it needed a complete rebuild. Just to compare, I wouldn't mind trying something with non-cat secondary burn technology. 
