Temperature set point differential....

[Lapeer20m]

I think this is the correct terminology.

I built my owb and I have the draft control set to shut off at 70* Celsius, and open at 60* celcius.

Another member suggested that this gap is much too wide and may be more efficient if I narrowed the temperature range. Ie: 2 or 4 degrees.

There are lots of experienced people here, what do u guys think?

 

[maple1]

I think with my old one, I had it set to close at 190°f with a 20°f differential.

It would depend though on your boiler & how quick it responds to the draft opening, and how much heat keeps building after the draft closes.