Jotul F3 - partial loss of secondary burn.

I've only had a few small fires this fall, and I noticed the secondary burn has greatly diminished. It was pretty decent last year, but not great. The stove has no problem putting out heat, but I think I am loosing some efficiency with this problem. I pulled the stove out and wanted to vacuum out the secondary air intake and check for dust or ash buildup. I removed the secondary cover and found the first slight issue of a partial blockage of maybe 1/3 of the intake. This was partially gasket material on the inside back wall with an accumulation of dust and ash buildup. I cleared it completely.



There is a cast iron restriction plug that covers about 2/3 of the total intake, I cleaned it and set it aside while I worked on the stove. Here is the plug in place.







I looked in the intake and saw some crumbled furnace cement blocking the air holes going into the firebox. At this point I pulled off the top of the stove and looked further. After a good vacuuming out, I found a bolt missing in the rear corner of the baffle that holds the stainless air distributor up to the baffle. Here is the shot of the missing bolt and this is the left rear corner where the secondary intake is.




After pulling out the assembly I found that the cement that seals the baffle to the distributor had crumbled and all the bolts holding this sandwiched assembly were loose in their holes.
This picture is looking through the secondary intake into the back of the air distributor. You can see the cement blocking a lot of the holes that lead into the firebox.




I removed the assembly and removed the bolts. Everything got a good cleaning and the channels that meet the two pieces were scraped out and wiped out clean. I put new cement back and replaced the missing bolt. I also re-cemented the gasket on the back wall where the assembly meets up and bolts pull them together. Now I have an airtight seal of the baffle and distributor assembly. There must have been so much air leakage into the assembly, it was pulling air from within the stove and not fresh air from the back secondary opening.

I also put some gasket around the exit collar. It basically goes through the back wall of the stove, and there is not flue collar. The bolts on each side pull it out of round a little, causing some air leakage to be pulled into the flue and not through the stove.




I still need to replace the door and glass gasket, but if the temps cool tonight, I am going to try this out and see if it is back in action. The corner seals of the stove plates were in very good shape, so a complete tear-down was not necessary. I leave the ash pan filled, so no worries about an ash pan gasket leak. This stove is from the 1990's, so it was due for some heavier maintenance than just the door gasket and cleaning.

 

It was also good to see the working innards and do a good inspection.

Every time I read your signature I wonder if I can squeeze a Castine in my fireplace opening with a short leg kit.