On Wed, 28 Jan 2015 04:03:13 -0800 (PST), wrote:

micky wrote: "Are you somehow giving the measured efficiency or the rated one? "

Measured - our provider measures it every other year or so, during yearly
maintenance.

How does he do that?

I can see putting some accurate gauge in the oil supply pipe. Does he
do that?.

But how does he measure the heat output?