I need some help. I have an old boiler in my 1868 brick house with the old-style steel horizontal expansion tank. The expansion tank has had it. I have patched the thing numerous times with epoxy putty but new leaks keep popping up. I would like to replace it with a bladder style tank but I am not sure where to the plumb the new tank and what changes (new valves, etc) I need to make to my system. Also, I am not sure what size bladder tank to purchase. I have looked at drawings of installations online but not sure how to relate it to my system.
I have a hot water system with finned baseboard radiators. The house is approx 4,000 sq ft. The boiler is natural gas Peerless 256,000 btu/hr. There are multiple zones. I know the smartest thing would be to replace the whole thing but finances do not permit. I had a company come out and their quote for replacement with a high efficiency unit was over $20,000.
To complicate things further, I have a daughter who was injured in a car accident who requires 24 hour care so keeping the system running without outages is important. We have a pellet stove and a wood stove that we use to try to avoid the natural gas bill from using the boiler but when the temperature drops too low we need to turn the boiler on. Any help would be appreciated, thanks in advance.