Water Heater Not Working? What to Check Before You Call

When a water heater stops working, a few simple checks can tell you a lot: whether every faucet is cold or just one, whether the breaker has tripped or the gas supply has stopped, whether there's water around the base, and whether the temperature setting has changed. Leave the rest to a licensed plumber. Don't relight a pilot, open a panel or touch the gas controls.

First: do you smell gas, or is water spreading?

Deal with these before anything else.

• If you smell gas (a rotten-egg smell) near the water heater or anywhere in the house, don't touch the heater, its controls or any light switches. Leave the house, and call your gas utility's emergency line or 911 from outside.
• If water is spreading across the floor, close your home's main water shut-off. If the heater is electric and the floor around it is wet, don't touch the heater: switch off its breaker at the panel, but only if you can reach the panel without standing in water. Then call a plumber.

Is it every faucet, or just one?

Run the hot water at the kitchen sink, a bathroom sink and a shower. If only one of them runs cold, the water heater is probably fine, and the problem is that faucet or its valve: book plumbing repair. If every hot tap runs cold or lukewarm, keep going down this list.

Did you just run out of hot water?

A tank holds a set amount of hot water. Back-to-back showers, a load of laundry and the dishwasher can use it up, and the tank then needs time to heat a fresh supply. In January the water coming into the tank is much colder than in summer, so it takes longer to heat, and the hot water seems to run out sooner.

Give it a while without using any hot water, then try again. If the water never gets hot, or runs out much faster than it used to, there's a problem to have looked at.

Electric water heater: has the breaker tripped?

Find the breaker labeled for the water heater in your electrical panel. A tripped breaker sits in the middle or in the off position. Switch it fully off, then back on, once.

• If the breaker trips again, leave it off and call. Don't keep resetting it: a breaker that trips again is a sign of a fault.
• If the hot water comes back, mention the tripped breaker when you next have a plumber in.
• Don't open the panels on the side of the heater. The thermostats and heating elements behind them are connected to live wiring.

Gas water heater: is gas reaching it?

• Check your other gas appliances. If the stove or furnace works, gas is reaching the house. If none of them work, contact your gas utility.
• Look for the flame, but don't touch anything. Some gas water heaters have a small window where you can see whether the pilot or burner is lit. If it's out, don't try to relight it. Call a licensed plumber or gas professional, because a flame that has gone out may have gone out for a reason that needs finding.
• Look at the vent pipe on top of the heater. It carries exhaust, including carbon monoxide, out of the house. If it has come loose, rusted through or been knocked out of place, have a licensed professional look at it before the heater runs again.
• Leave the gas valve and the control knob alone.

A gas water heater burns fuel, so the home should have working carbon monoxide alarms. If yours has none, or you're not sure they work, book smoke and carbon monoxide detector installation.

Has the temperature setting changed?

If you can see the setting without opening anything, check whether it has been turned down, or set to a vacation mode, since you last had hot water. That alone can explain lukewarm water. Just look: on a gas heater the dial is part of the gas control, and on an electric heater the thermostats sit behind the panels, over live wiring. Tell the plumber what you saw.

Is there water around the base?

Without touching any electrical parts or gas controls, look at:

• the floor under and around the tank;
• the pipes and fittings on top;
• the relief valve, on the top or upper side of the tank, and the pipe that runs down from it.

A drip from a fitting on top may be a loose connection. Water coming from under the tank may be the tank itself. A plumber can tell which.

If water is coming out of the relief valve's pipe, the valve may be letting off pressure or heat. Never cap, plug or remove that pipe or the valve. Call a plumber.

What else should you note for the plumber?

• Rumbling, popping or banging from the tank.
• Rusty or discolored hot water, while the cold runs clear.
• A smell in the hot water from the tap. A smell in the air near the heater is different: treat it as gas.
• The label on the tank. Photograph it: it shows the brand, model, size and fuel, and the label or serial number often shows when the heater was made.

When should you call a plumber right away?

Call if:

• water is leaking from the tank, or from the relief valve's pipe;
• the breaker trips again after one reset;
• the pilot or burner is out on a gas heater;
• the vent pipe is loose or damaged, or you see scorch marks or soot around the heater;
• there's still no hot water after the checks above.

Book water heater repair and installation, and have your photo of the label ready.

Do you need a permit to replace a water heater in Virginia?

It depends on the fuel, and for an electric heater on where you live. As of September 2026:

• Gas: yes, even like for like. Virginia's building code exempts some equipment replacements, but not equipment fueled by gas or oil, and both Fairfax County and Prince William County require a permit.
• Electric, same size in the same place: Fairfax County requires a permit, and Prince William County doesn't. Elsewhere in Northern Virginia, check with your county's or city's building department.
• In an emergency, the replacement may start before the permit is issued, as long as the application is filed by the end of the next working day (13VAC5-63-80). Agree with the plumber on who will file it.

Who can work on a water heater in Virginia?

Repairing or replacing a water heater for pay is plumbing work, plus gas or electrical work. In Virginia it needs a tradesman license from DPOR, the Department of Professional and Occupational Regulation, or the supervision of someone who holds one (Va. Code § 54.1-1129, as of September 2026). A business that contracts a job worth more than $1,000 also needs a DPOR contractor license. You can look up a plumber's license for free on DPOR's License Lookup. This is general information, not legal advice; confirm with DPOR.

Get the hot water back on

If the checks above didn't bring it back, book water heater repair and installation with an independent local Pro.

Last updated September 2026.