On Sun, 24 Jun 2012 15:01:42 -0400, Jim Wilkins wrote:

"Winston" wrote in message
...

(...)

Perhaps I'll put an IR photosensor aimed at the burner. Or a
thermocouple nearby. Haven't decided.

--Winston

I'd put a thermocouple in the flue and capture both timing and heat
loss.

Yup. That flue does get pretty hot.

Probably couldn't hurt to replace it with an insulated flue.

--Winston