So, when I had my stoves cleaned out this past summer, the guys doing the job commented that my one stove was the biggest mess of creosote they’ve ever seen. They literally had to spend more than an hour with hammer and chisel, chiseling the bricks out of the rear corner, which were glued into the stove with creosote. The job was more than half finished before I got home (they arrived much earlier than scheduled), but given the racket they were making with the hammer and chisel, I just hope no welds were broken on that relatively thin steel box.
While the firebox was a mess, the chimney was clean, indicating the cat was doing its job, and that my burning habits aren’t all THAT bad. Also, I have two of the same stoves at opposite ends of the house, and the other Ashford was “normal”, in their words. Only one was badly gunked up, and it seemed to be concentrated in the rear of the firebox.
Summary of the two stoves:
Dirty stove (hereafter “stove #1”): Installed on 15 feet of pipe, run on 24 hour reloads, heating < 2000 sq.ft. Located in a deep exterior stone fireplace, with approximately 1 foot of space behind stove to rear wall of fireplace.
Clean stove (hereafter “stove #2”): Installed on 30 feet of pipe, run on 12 hour reloads, heating 4000 sq.ft. Located in shallow exterior stone fireplace, such that back of stove is only 4” from rear wall.
Without boring everyone with every detail of my reload and operational procedure, I’ll point out a few things that I think might be contributing:
1. I leave my fans running, on a very low setting, all of the time. I do not shut them down when reloading. I had previously thought the only reason for shutting off the fans would be to get a more accurate cat probe reading (fans blow across probe shaft on the Ashford 30), and I really don’t need a more accurate cat probe reading, my clean chimney being good evidence that I’m getting good cat response.
2. I typically run the stove on high for 15 minutes before closing the bypass damper, while the fire gets going, and then another 20 minutes after. This is based on the manual instructions to “run the stove on high 20 - 30 minutes, or until the fire is well established.” After this, I turn the t'stat to about 4-o'clock, which is what gives me a 24-hour burn.
3. This stove is run every day, all day, on cycles of at least 24 hours. In the shoulder seasons, I will sometimes run it on 30 - 36 hour cycles, or whatever I can get out of it. During the bulk of the winter it’s loaded every 24 hours, and run down to coals between loads.
Knowing there is (or at least was, before all that hammering of chisels) no leak in the firebox, as evidence by my ability to maintain 30+ hour burn times, I am beginning to suspect that running the fans during that 20 - 30 minute wide-open burn are the cause of this mayhem. Could they be cooling the outer steel of the firebox sufficiently, to prevent any creo that collects between the bricks and steel to not burn off, as intended?
Should I become more concerned with my wood quality? I haven't MM'd the wood in several years, knowing it's been stacked > 2.5 years outdoors, and top-covered before our fall rains start each year. It seems dry to me, and the cats always light-off without issue, but maybe it's not dry enough for 24+ hour burning.
Or, is this just what anyone would expect, when a stove is run day-in / day-out on long 24-hour burn cycles, and never pushed any harder? Now, before you King guys answer, and say 24 hours is nothing, remember this is a much smaller stove, so the burn rate I have to maintain for 24+ hour burns might be more like your 40+ hour burn rates.
Thanks!
