How to Troubleshoot and Repair an Electric Water Heater

If your water heater is not working, you don't necessarily have to call in the pros or spring for a water heater replacement right away. DIY electric water heater repair is an option, depending on the problem. But first, you'll need some knowledge to diagnose your water heater problem.

Electric water heaters look similar to their gas-fueled cousins. They both use an insulated storage tank jacket made of steel, with insulation between the storage tank and the tank jacket to reduce heat loss of the heated water. The main difference between electric and gas water heaters is the heat source. In an electric water heater, the water is heated by electric upper and lower heating elements that extend into the water tank. Gas water heaters have a gas burner that heats the water from below the tank.

One of the most common problems with electric water heaters is a failed heating element, which results in little to no heat production. Fortunately, it is an inexpensive part that is relatively easy to replace with DIY water heater repair. Other common problems that could cause your hot water heater to stop working are improper settings, high home water pressure, or a lack of tank maintenance.

If you're considering DIY electric water heater repair, here are seven common problems and potential fixes.

Before You Begin: Check the Warranty

Before you start to troubleshoot your hot water heater problem, check the appliance's warranty. Both residential and commercial hot water heaters come with limited warranties. On every tank is a rating plate with the model and serial number. These numbers detail the year the tank was made and will determine whether the tank has a prorated warranty that might offer a new tank or parts, either free of charge or at a discount.

Take a picture or write down the information, and call the manufacturer if there are signs of your water heater going bad, such as a limited hot water supply in your home. But note that manufacturer warranties typically do not cover field labor.

No Hot Water

A water heater that produces no hot water might not be getting power, might have a tripped limit switch, or might have one or more failed heating elements.

How to Fix

First, check the water heater's circuit breaker in the service panel to make sure it hasn't tripped. If the breaker has tripped, switch it off and then back on.

If the heater's breaker did not trip (if it is still on), try to reset the high-temperature limit on the heater:

1. Turn off the breaker to the water heater's circuit in the service panel.
2. Remove the access panel for the upper heating element on the water heater.
3. Remove the insulation and the plastic safety guard, being careful not to touch any wires or electrical terminals.
4. Press the red button—the high-temperature cutoff reset button—located above the upper thermostat.
5. Replace the safety guard, insulation, and access panel.
6. Turn on the heater's circuit breaker.
7. If that doesn't solve the problem, test each heating element and replace it if necessary.

Inadequate Hot Water

If your water heater is producing hot water but not enough of it, your unit could be too small to meet the household's hot water demand. Make sure the demand does not exceed the capacity of the water heater.

How to Fix

The water heater should have 75 percent of its capacity as hot water. For example, a 40-gallon water heater is properly sized for a demand of 30 gallons. If the demand is too great for the heater capacity, try to limit the length of showers, install low-flow shower heads, and spread out dishwashing and laundry to different times of the day instead of doing them simultaneously.

If your unit is not undersized or it suddenly produces less hot water than it used to, one or both of its heating elements might have failed and will need replacement. A constant supply of lukewarm water during a shower is indicative of a defective upper heating element. Hot water that runs out quickly during a shower is indicative of a defective lower heating element.

Water Temperature Is Too Hot

Too much hot water can be almost as frustrating as not enough hot water. If you're experiencing this problem, one or both of your water heater's thermostats might be set too high.

How to Fix

To check the thermostat settings:

1. Turn off the power to the water heater in the service panel.
2. Remove the access panel, insulation, and plastic safety guard from each heating element on the water heater. Do not touch any wires or electrical terminals.
3. Test the wires to confirm the power is off, using a non-contact voltage tester.
4. Check the heat setting on both thermostats; they should be at the same temperature. The recommended setting is roughly 120 degrees Fahrenheit.
5. Adjust the temperature to the desired setting, using a flathead screwdriver.
6. Adjust the other thermostat to the same setting.
7. Replace the safety guard, insulation, and access panel for each element.
8. Turn on the heater's circuit breaker.

Water Leaks

Water leaks usually are caused by leaking valves and plumbing connections, but they can also be related to tank problems. Leaking water can cause significant damage to a home, so it is important to fix the leak as soon as possible.

How to Fix

Leaks from water heater tanks can be due to loose heating elements or tank corrosion. Inspect the elements for looseness, and if necessary tighten them with an element wrench.

A corroded tank cannot be repaired and must be replaced. Turn off the power and water supply to the water heater, and then drain the tank completely to stop the leaking.

Rust-Colored Water or Bad Odor

If your water comes out of the faucet with a brown, yellow, or red tint to it, there could be corrosion occurring inside your water heater tank or in the pipes in your home. Similarly, if your water comes out smelling like rotten eggs, there could be bacteria in the hot water heater tank.

How to Fix

You might need to replace the anode rod in the tank, which typically requires the services of a professional plumber.

Tank Making Noises

Are there noises coming from your water heater? Does it sound like a low rumbling or popping noise? Or maybe it's a high-pitched whine? The noise you're hearing might be the sound of boiling water. Excessive buildup of sediment in the bottom of the tank can cause the bottom of the tank to overheat, which results in boiling the water.

How to Fix

The first solution to try is to drain the tank to get rid of the sediment. If that doesn't help, you might need to replace the tank.