At 08:03 PM 9/15/2015, SDF ( aka ;jim lahey' - Scott ) wrote:
>needless to say, what temp it starts to open at would depend on the
>temp rating of the t-stat.

Numbers are straight out of Bentley for stock 87C thermostat.

>if Don has a 'par' value stat ..say 180F ..
>I would expect start of opening to be a bit above 170 F or so.
>
>and why not use water ? that's what the books show I believe.

Water will only get you to 100C at sea level.  If you want to check
for full opening you have to get to over 105C.

Yrs,
d

>Scott