"tp" wrote in message ...

Hi Group

Could I correctly assume, that the following data
shown on my furnance indicate its 80% efficiency ?

Make: Anthes
Model: LN 140 HAAAA
Burner Input: 140,000 Btu/hr
Bonnet Output: 112,000 Btu/hr
Year: not provided

Does anybody have a clue, how old this unit could be ?

Regards
Tad

No, my 29 year old Lennox has the same ratio but is only about 60% AFUE.
That is steady state output not taking into account start stop cycles, flue
draft waste etc