[Richard]

You should test it of course, but the battery that was boiling is likely beyond salvage. I highly suspect a bad or shorted cell in that particular battery.

There are two competing schools of thought on replacing the battery. One is that all batteries in a bank should be replaced at the same time. The second is just replace it. Depends on your budget and how much you boondock. You may even think about just running with one less battery if you mostly go pedestal to pedestal.