GENERATORDB
125 units

What size generator to run an electric water heater?

Electric water heater draws about 4,500W while running, and being a resistive load it has no startup surge. Allowing 20% headroom, size for at least 5,400W of starting capacity.

Resistive and enormous. Most backup plans simply do without hot water.

Units that cover it

Running more than one thing

Most people are not powering one appliance. Add everything you need at once and the calculator works out the real peak — your total running load plus the single largest surge, not the sum of every surge.

Size the whole load

Other appliances