What to Do When There Is No Hot Water

If you suddenly have no hot water, start with the basics. On a gas water heater, check that the pilot light is lit and the gas supply is on. On an electric water heater, check whether its circuit breaker has tripped. If only one faucet is running cold, the problem is at that fixture, not the water heater. If the tank is leaking, or the basics check out and you still have no hot water, it's time to call a plumber.

Check the water heater

The first thing to check is the water heater itself. If it's turned off, the pilot light has gone out on a gas unit, or the breaker has tripped on an electric unit, it won't produce any heat. Relight a pilot only by following the instructions on the heater's label. If a breaker trips again after you reset it, leave it off and call a plumber, because something is wrong.

Test the temperatures

Turn on the cold water at a faucet and check it first. It should run cold with normal flow. If it doesn't, you may have a bigger problem with your water supply, and you should call a plumber.

Next, turn on the hot water. It should be hot, but not scalding. If it isn't hot at any faucet in the house, the problem is likely with your water heater.

Check the water heater's cold water supply valve

Your water heater has a shutoff valve on the cold water line that feeds it, usually on the pipe at the top of the tank. Make sure it's fully open. If it was closed, the tank isn't refilling with water to heat.

Adjust the temperature setting

If the thermostat is set too low, the water heater may not be heating the water enough. On most gas water heaters, the temperature dial is on the gas control valve near the bottom of the tank. On an electric water heater, the thermostats sit behind access panels on the side of the tank. Turn the power off at the breaker before you open those panels, because there are live electrical parts inside.

Around 120°F is a commonly recommended setting. Check the label for your heater's recommended settings and don't exceed them, since that can damage the unit or create a scalding hazard.

If adjusting the temperature doesn't solve the problem, there may be another issue, like a faulty thermostat or a heating element that needs replacing. In that case, contact a professional plumber, who can diagnose the problem and make the repair quickly.

Look for leaks

Next, check around the water heater and along the hot water pipes you can see, including valves and connections. Water pooling under the tank usually means the tank itself is failing, and that calls for a replacement rather than a repair.

A small drip at a threaded fitting can sometimes be fixed by tightening it or resealing the threads with plumber's tape. For anything more than that, or any sign of water damage, it's best to call in a plumbing professional.

When should you call a professional?

If you've tried all of the above and still have no hot water, it's time to call in a professional. You may need a new heating element or thermostat, or there may be a problem that takes special attention and expertise to diagnose.

A plumber can also check for sediment and mineral buildup inside the tank, which is common with our hard water and makes a water heater less effective over time. Many of these problems are relatively easy to fix, and calling in an expert gets you to the root of the problem quickly so you're back up and running with hot water as soon as possible. Our water heater team repairs and replaces all types of water heaters.

If your water heater is getting older, see is now the time to replace your old water heater? And if a failing tank is leaking into your home, call our 24/7 emergency line.