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Went on a side job last night for a leaky pressure relief valve on the boiler, replaced valve but before I did i noticed the system was at 30psi (the PRV is 30psi 550,000 BTU water reg valve is a wats 12-15psi). Checked the 30# expansion tank and it is full but still has air so I know the bladder isn't ruptured. Determined that the expansion tank is to small for the system, jumped online to look for the next size up and noticed the Extrol 30# and 60# both say the accept 2.5 gal of water. Question is will I be fine with the 60#?
Could I twin two 30#?
The one that is there currently is hung on the wall down by the floor then piped up to the spiro.
the system has three zones of copper fin baseboard on the first floor and one hydro-air coil on the second floor (manual says it's 100,000btu coil)