If it happens occasionally for short times, I don't think there's a big deal. Consistently and for long may be a problem.
So if you want to run the insert hot (to clean out the gunk inside that accumulates when you run low and slow), do so with the thermostat maybe a bit less than fully open. My thermostat has the minimum at "1 o'clock" and the max at 6. I do my occasional hot runs around 4.30-5 ish on the thermostat.
I know folks in Alaska run wide-open-throttle sometimes for long. But it all depends on the draft so comparing is hard to do.
I don't know if you have a ceramic cat or a metal one; it's easier to see flame impingement damage to ceramic cats. (but once that happens damage has already occurred).
So if you want to run the insert hot (to clean out the gunk inside that accumulates when you run low and slow), do so with the thermostat maybe a bit less than fully open. My thermostat has the minimum at "1 o'clock" and the max at 6. I do my occasional hot runs around 4.30-5 ish on the thermostat.
I know folks in Alaska run wide-open-throttle sometimes for long. But it all depends on the draft so comparing is hard to do.
I don't know if you have a ceramic cat or a metal one; it's easier to see flame impingement damage to ceramic cats. (but once that happens damage has already occurred).