Clare furnace 1981

Please identify if the Clare furnace 1981 Mod LBG 125, Ser 53750
is a conversion unit, mid or hi eff. The furnace has a single burner, spark
igniter

Thanks

My guess is that it is a conventional unit (updated)

Mid efficiency units have a metal vent and metal exhaust fan in the burner compartment

High Efficiency units have plastic venting and a plastic fan in the burner compartment.

Hope this helps

Cheers

Thanks Douglas