Generator for Electric Water Heater: Wattage Needs

Why an electric water heater matters for backup power

An electric water heater is one of the larger electric loads in a Texas home. It heats stored water with electric elements, and when an element turns on, the draw is noticeably higher than at other moments in the house. That makes the water heater a central question when you choose backup power before winter storm season or summer heat, especially if you live in a rural home or a home on a well.

Electricity is measured in units of power called watts, as the EIA explains in its measuring electricity page in the source list. The EIA also reports that the average U.S. household consumes about 10,500 kilowatthours (kWh) of electricity per year, and that home electricity use varies widely by region and home type. A water heater is part of that household total, but the figure that matters for backup power is the rating on the water heater itself, not an average.

Start by reading the preparedness pages: the Texas Division of Emergency Management and Texas Ready publish all-hazards guidance for Texas families. Read those pages as you plan a backup power purchase, then compare generator listings with the water heater nameplate.

• Read the generator listing's first watts figure and the running figure on the maker's page.
• Read the water heater nameplate to find its electrical rating.
• Ask a licensed electrician whether the generator can serve the water heater and how it connects to the home.
• Check the Texas Division of Emergency Management and Texas Ready pages before storm season.

Starting watts and running watts on a generator listing

A generator listing shows a watts figure in the title. On this site, the first watts figure is the starting figure, the higher moment when a motor or a heating element first turns on. The running figure, what the generator can supply steadily, is the second figure on the listing or on the maker's page. The Running Watts vs Starting Watts article explains the two figures in full.

An electric water heater's elements turn on and off as the stored water temperature changes, so the starting figure matters at the moment an element switches on. Compare that figure with the water heater nameplate, and read the How to Calculate Generator Wattage for a Home article to see how the site groups listings by watts for home essentials.

The catalogue states the first watts figure grouped, so the comparison works in groups rather than exact numbers. The maker's page for the generator usually lists the running figure and any limits, and the water heater maker states what the water heater requires. Read both pages before you compare.

Read the water heater nameplate before you compare listings

The water heater's nameplate, usually on the side of the tank, states its electrical rating. That rating is the figure to compare with a generator listing. The water heater maker can also state what the unit requires, including the size of the circuit it is on.

This site does not size a home. The decision of whether a generator can serve your water heater, and how it connects to the home, belongs to a licensed electrician who reads the water heater rating, the generator listing and the home wiring. Ask the electrician before you buy.

If your water heater runs on natural gas or propane rather than electricity, it draws much less power, but it is still a fuel-burning appliance that needs venting. The EIA explains that natural gas is a fossil fuel whose largest component is methane, and that hydrocarbon gas liquids such as propane are hydrocarbons that occur as gases at atmospheric pressure. For the backup power question on the gas side, read the gas water heater power article.

Compare generator types by their listed wattage figures

Portable generator listings show the first watts figure and add feature words such as electric start, RV ready and CO sensor. Inverter generator listings carry the same figure with inverter in the title. Standby generator listings are installed units with a kilowatt figure, and a licensed installer connects them. See the standby vs portable comparison.

For a Texas home on a propane tank, a dual fuel listing adds propane as a fuel word; read the dual fuel: propane vs gasoline article. For a close neighborhood, an inverter listing is a type choice rather than a statement about sound level. For any generator, the outlet set matters; read the outlets and plug types article.

Brand names such as Generac, Champion and Westinghouse appear in portable titles; WEN and GENMAX names also appear. A model name tells you the model, while the feature words tell you what the listing claims. The buying guides compare the stated details, and the table at the end of this article points to the matching guides by situation.

What this site cannot say about an electric water heater

The catalogue has no measured output, running watts, runtime, fuel use, outlet or emissions data. An article explains what a term means on a listing and points you to the listing and the maker's page. The site does not promise that a generator runs an appliance, does not give load or runtime sizing, and does not give wiring, fuel storage or placement advice.

The maker's manual, a licensed electrician and the local permit office decide the installation and the connection. When a listing includes a CO sensor and shutoff, follow the maker's manual and read the CPSC, CDC and NFPA carbon monoxide pages for generators in the source list before you run one. The CO shutdown sensor article explains the listing word.

What to pick for your situation

Questions

What do the wattage figures in a generator title mean?

The first watts figure in a title is the starting figure, the higher moment when a motor or heating element turns on. The running figure appears as the second figure on the listing or on the maker's page. The Running Watts vs Starting Watts article explains both figures in full.

Can a generator run an electric water heater?

This site cannot promise that any generator runs an appliance. Read the water heater nameplate, read the generator listing, and ask a licensed electrician whether the generator can serve the water heater and how it would connect to the home.

Should I back up an electric water heater or a gas water heater?

An electric water heater draws a large load when its elements heat. A gas water heater draws less power but is a fuel-burning appliance that needs venting. The water heater maker and a licensed electrician decide what the unit requires. Read the gas water heater power article for the gas side.

Does this site say what size generator I need?

No. The site explains listing terms and compares the stated details in its buying guides. A licensed electrician and the local permit office decide the size and the connection for a particular home.

What should I read before I buy before storm season?

Read the Texas Division of Emergency Management and Texas Ready preparedness pages, read the water heater nameplate, and read the generator listing and the maker's page. Then ask a licensed electrician before you buy.

What does a CO sensor and shutoff mean on a generator listing?

A CO sensor and shutoff is a feature listed on the unit; the listing words describe the feature. Follow the maker's manual and read the CPSC, CDC and NFPA carbon monoxide pages in the source list before you run a generator. The CO shutdown sensor article explains the listing word.