Electric tank boosters from Rheem, 240V, drawing 30 to 54 amps, with 1/2" and 3/4" MIP connections.
A tank booster raises the output of an existing water heater rather than replacing it. It sits downstream and adds heat on demand, which lets a tank that was adequate before an added bathroom keep up without pulling the original unit out.
The amperage is the constraint. A 54-amp booster needs a dedicated double-pole circuit and panel capacity to match, and on a service already carrying an electric range and dryer that is often the deciding factor.
There is a second use worth knowing: a booster can deliver the higher temperature a dishwasher or a commercial sanitizing rinse requires, while the main tank stays at a safe distribution temperature. That combination usually needs a thermostatic mixing valve on the branch that feeds fixtures.
Not a substitute for a correctly sized heater on a system that runs out routinely — a booster covers a peak, not a chronic shortfall.
