Ok, dumb question: How do I tell if my house's boiler and heating
system is hot water or steam? I'm confused because I've had 3 plumbers
in for estimates to replace my boiler - 1 says it is steam, 1 says it
is hot water, and the 3rd wasn't certain but thought it was hot water.
I'd always thought it was hot water, but I want to be certain.
My house has an old cast iron Ideal Redflash boiler from the American
Radiator Company (which changed names in 1929 the year our house was
built, so I'm pretty sure this is the house's original boiler) that I
believe burned coal originally but now burns oil. There is no sight
glass on the boiler, which makes me think it is hot water, but I also
can't find any expansion tank, which makes me wonder (I've checked all
closets, attic, etc. - where could it be hidden?). The psi on the
system is around 15, which also makes me think it is hot water (too
high for residential steam). The radiators around the house are all
old cast iron 2-pipe jobs.
How can I figure this out for sure?