Edwin Pawlowski wrote:
"GB" wrote in message

It's on the spec sheet after they clean and service it.
87%.
I thought that meant efficiency but maybe it means something else.


I have the same thing and yes, efficiency. . Reads 87.5% one year, 88%
another year, after cleaning. My heater is 28 years old.


That is a gross efficiency number, really a blind friggin guess, not an afue