I get a clunk when the bypass first drops shut, then a snap/clink sound (and feeling) when it locks in on my new Princess.
An update: last night I ran a test with a full load of cedar. I used just the cedar because I'm sure that stuff is dry--you can practically light it with a match and no kindling. I started her up at 3pm and lowered down to #1.25 on the thermostat, in increments, by 4:40. Then I let it run. Now this is below the lowest level I'd been successful at before (#1.5). As I expected, the fire "went out", by which I mean there was no visible glow in the firebox and the flue and cat temps started dropping. But something surprising happened a full hour later--the coals started glowing again, and some small wisps of blue flame appeared. The Princess followed this cycle, about an hour "off" and an hour "on", all the while maintaining roughly 300F on the stovetop. There was very little wood left when I went to bed at midnight, so I'd call that a 9 hour burn cycle on #1.25 with very dry, low-BTU wood.
Is this normal for you guys, when burning at a low setting (cycling between on and off)? Or does it indicate I'm having a draft problem?
To diagnose the potential draft problem, I got a Dwyer Mark II manometer. Given my flue gas cools rapidly in the single-wall pipe, any ideas where would be the best place to probe the flue for draft? Obviously I can't get too close to the stovetop without melting the probe tube.
BTW I'm running the same test today with a load of oak. At least a couple of the pieces I put on were damp--didn't measure a fresh split but they were hissing as they started to burn--so I think y'all are right that moisture content could play a role in some of my issues. I think the guy sold me a mixed lot of variously seasoned pieces, because some measure drier than others.