efficiency of +20 year old Weil-Mclain oil boiler P366(HE)?

[hillpc]

The boiler with Beckett AF burner was here when I moved in. I assume
the HE stands for high efficiency, but what was that 20 years ago? I
could keep this boiler going for a long time, but wanted to check if
it's worth it to replace with new. The Weil-McLain website has a
calculator but doesn't have the info I need. It shows a 78% default
efficiency; going from this to 86% or so saves me a little over $200/
year (at $2.40/gallon). Seems like that'll take quite a while to
recoup at a boiler equipment only cost of over 2 grand.

[flamefix]

The boiler with Beckett AF burner was here when I moved in. I assume
the HE stands for high efficiency, but what was that 20 years ago? I
could keep this boiler going for a long time, but wanted to check if
it's worth it to replace with new. The Weil-McLain website has a
calculator but doesn't have the info I need. It shows a 78% default
efficiency; going from this to 86% or so saves me a little over $200/
year (at $2.40/gallon). Seems like that'll take quite a while to
recoup at a boiler equipment only cost of over 2 grand.

A flue gas analyser with the oil flow rates set should give you some idea of the efficiency. A modern condensing oil boiler will give you 95-7% efficiency.