My mom has an old gas water heater. The county sent her a notice saying she had to get an expansion tank. That costs a couple hundred bucks by itself. So, she figured she would just get a new water heater and expansion tank installed.

A plumber we use regularly recommended the Rheem 22V40FI (about $750) installed. It is not energy star rated and the plumber did not advocate that she spend more for an energy star rated.

I was wondering:

1. Because there is a $300 tax credit for certain energy star models, would it make sense to get one and, if so, which one?

2. Should she consider an electric or electric heat pump water heater instead? She lives in Atlanta. Any reason she can't get one because she has a gas water heater now?

3. Any other alternatives or things I should consider in this significant purchase? Like an extended warranty (I loathe them usually)?

Thanks!