Nice unit - heat pumps are real money savers - your utility bill will look much different next month. Keep in mind many local utilities give you a rebate on your purchase for installing an energy efficient heat pump.
Unfortunately for me, an 'off the shelf' heat pump water heater won't fit in the basement where the heater currently is. There are mini-split type ones, but their rarity means much higher prices.
We're installing minisplit HVAC in 1/3 of the house next week, to take the $2k federal credit next year. Another minisplit HVAC in a different 1/3 of the house arrives in January to get that credit in a different tax year. We will put in the HP water heater sometime after that. Not clear if I can capture the credit the same year as either of the HVAC rigs. After that, my oil burner is strictly a backup system.
Got a quote on five mini splits, $35,000. We’ll probably stick with the window units unless I get motivated to try a diy system
If you have time-of-use electrical billing, a timer can help you reduce electrical water heating costs. My electricity triples in price between off-peak and on-peak. Be warned, if you keep the temp set too low you can get bacteria growth making it either stinky or even harmful for your health if you get Legionella growing. I use a timer to shut off the heat in peak periods and I set the water temperature at the high end 140oF If you don't use a lot of water then you won't save as much. YOU have to quantify how much water you use if you want to know how much you can save in water heating costs
There are some ridiculous State-level incentive programs available in Massachusetts, if that happens to be where you are installing these.