I have a Sta-Rite max e therm heater. Rats made a nest for who knows how long their pee rusted out the top of the combustion chamber. I was thinking about buying a Pentair heater to replace it. I read they are the same internals. Will the water and gas connections line up on the Pentair or will I have to replumb it? If any new plumbing is required I might go with the Raypak.