I've been enjoying reading all these threads now that I've become a homeowner. Been trying to educate myself on my home's old gravity boiler. Home inspector said (before we bought house) that many homes here in South Minneapolis still have these original boilers, and though not the most efficient, they perform beautifully and will last if properly maintained. This one is original to our 1934 house. We love the radiators that heat each room in our main floor.(No rad in the finished/converted attic, or in unfinished full basement).
I just had the boiler cleaned and tuned,tested for CO. Replaced
the thermocoupler. Tech said everything checked out great. With our programmable thermostat, I keep the house at 70 while we're at home. At night, therm goes down, and we use oil-filled radiator in our bedroom (if needed). Even in cold Minneapolis, my gas bills are under $200/month. Not too bad, compared to many.
I wonder if it would be possible to add a radiator up in the finished attic? There's no heat source there, so an oil-filled radiator with a timer heats the space adequately when we are in the space, but it does use the electricity. Would tapping the existing send and return lines to send water up to a second floor radiator throw everything off balance? Would it even be cost effective over time?
I've attached photos for your inspection of our old Weil-McLain.