Received this link in an email today, thought it might be useful
There is some models that I carried when I had the heating and cooling company that is inaccurately listed. DO NOt treat this list as gospel.
I do not see Arkla Servel- Natural Gas Air conditioning with Ammonia heat exchangers from 50’s to 70’s
I’m looking for the age of a Lennox oil fired steam unit model # CDB-E3.7