This afternoon, I sat in on the (virtual) Glasgow Worldcon bid party (via Zoom) during Octocon, the National Irish Science Fiction Convention, but logged out when Steve arrived. I wore my face mask while he was here, and I'd previously tried to ventilate the living room for his sake. Fortunately, the weather was mild this afternoon.
Steve spreads old sheets on the floor and tapes them over the chimney so that debris doesn't spill out. He then goes up on the roof and uses brushes and a Shop-Vac to clean accumulated junk from the inside of the chimney. As we mostly burn the pressed-sawdust fire-logs, we don't get a whole lot of build-up, but there's enough to justify cleaning it annually.
After cleaning the chimney, Steve and I pulled our O2 insert fireplace out of the surrounding masonry to allow access to clean around the back. Steve vacuumed it out as well as vacuuming the debris that had fallen down the chimney as he was brushing it. the box at left holds the new O2 catalytic element, about which more later.
This is what it looks like behind the stove when it's pulled out.
Normally, Steve and I would push the stove back into place, but I told him to leave it out because Lisa and I needed to do a piece of maintenance on it, and in case we needed to get at it from above or behind, we might as well leave it sitting out.
These O2 stoves contain a replaceable catalytic element that makes for more complete combustion. It's not quite clear how often it should be replaced, but we've been here ten years, and we have no idea how long it had been since the stove was installed or if the catalyst had ever been replaced, so this summer I ordered a new one, which costs around $250.
The bracket that holds the catalyst hangs just inside the stove firebox held by four bolts. Lisa applied WD-40 to loosen them and used a box ratchet from her store of Snap-On tools bought for her by her mother long ago, while blessing her mother's memory and pointing out that high-quality tools make jobs like this vastly easier.
After eventually working the nuts loose, she was able to remove the bracket, which I took outside and from which I removed the old catalyst. There was plenty of junk accumulated inside the bracket. Lisa took it out onto the sidewalk and knocked all of the crud out of the bracket after I took this picture. You can't see it that easily here, but the grid is deformed and isn't level. The catalyst still fits, but in ten years or so when we replace the catalyst, I may want to see if I can replace the entire bracket as well.
Here's the old catalyst at left (it's cleaner than I expected) and the new one at right. I put the old catalyst in the box in which the new one shipped, in case for any reason we need an emergency replacement catalyst. After I labeled the box, Lisa stored it in the garage.
With the new catalyst installed in the bracket, we were able to take it back inside, where Lisa managed to lift it into place and re-attach it with the four nuts. It's not a particularly clean job. While it turns out that we did not have to access anything through the top or back of the stove, Lisa says that it was easier for her to reach the catalyst bracket while it was pulled away from the wall.
With all cleaning and maintenance done, Lisa and I shoved on the stove, which was reluctant to go back into the wall until Lisa stuck the piece of rebar that we use as a wood poker under the stove and pried it up enough so that we could get the leverage we needed to push it back into place.
After cleaning up, we determined that this was more than enough work for today. As a bonus, though, we brought the swamp cooler back inside and stored it away for the winter.
It probably won't be that long before we have to light a fire in the fireplace, and now we know it's clean and prepared for another winter. We expect it to burn cleaner than it has in the past, especially if we can still get the pressed-sawdust fire-logs, which already produce very little ash and only much visible smoke when first lighting the fire.