Boy, this brings back some memories. In 1956 I went to work as a sixteen year old helper for a plumbing and heating contractor. Those threaded pipes behind the mechanic are 1 and 1/4 inch black iron pipe that I had to cut and thread by hand, apply single strand lamp wick and pipe joint compound to the threads. and either hand it to the mechanic or put it together myself, under his direction of course. No copper, sweat/soldering, plastic or glue used here. This is a hot water hydronic heating system as can be confirmed by the "T" shaped fitting on top of the boiler, and the malleable black fittings into which the pipe is screwed. What is missing from the installation is the paper/cardboard insulation on the pipe sections, and then after mixing dry asbestos with water to the consistency of cement, this was troweled on all the fittings in an effort to maintain hot water until it reached the radiators located throughout the building. That right folks dry asbestos floating so thick in the confines of a boiler room or basement, that one could hardly see the other side of the room. Ah, those were the days!

Feel better Dave? Must be nice to know everything.

[I don't know everything, but I do know the difference between carbon monoxide and carbon dioxide. - Dave]

A Bacharach "Fyrite" combustion analyzer, which has something to do with measuring carbon dioxide, or CO₂.

I don't know if I'd want this crazy-looking furnace mechanic in my basement!

It will never be that clean again.