No, the breaker you have now is too small. The '25' on the breaker handles means its a 25 amp breaker; it's a 240 volt, double pole, 25 amp breaker. You need a 30 amp, double pole breaker for the new 5500 watt heater and 10 gauge wiring to the unit.

Great, thanks. Do you think a 4500 watt electric hot water heater go on this double pole breaker?

Hire an electrician for the sake of your family if not yourself.

Great thanks for your input! I’m not actually doing the electrical work myself I’m just picking out the hot water heater and want to keep costs down with the plumber and electrician.

There's a point of discussion as to whether a water heater is a continuous load or not. I tend to think not. Mine does not run for 3 hours straight.

@bryanthegrower: "Hire an electrician for the sake of your family if not yourself."

Oh, come on. He's just checking to see if he's buying a water heater his 240 volt circuit will support. And you don't need an electrician to install a hot water heater. Connect three wires and you're done.

Thanks! Yeah I am Just trying to keep costs down and want to make this easy and cheaper for my plumber To switch out from the old one.