How To Troubleshoot A Water Heater

A water heater
  • 1-2 hours
  • Beginner
  • 50-125
What You'll Need
Voltage meter
Water heater element wrench
What You'll Need
Voltage meter
Water heater element wrench

If you own a home, chances are you will eventually face a failing or malfunctioning water heater. It could be as simple as lukewarm water in the shower or the more serious problem of a leaking water heater. In either case, being prepared by knowing how to troubleshoot the problem could save you from an expensive repair bill and/or additional water damage to your home. Let's look at the necessary steps to identify a water heater problem as well as offer handy tips that could help you track down and repair minor problems yourself.

Water Heater Basics

The main components of an electric water heater are the insulated tank, heating elements, thermostat, pressure relief valve, drain cock, as well as the electrical and plumbing connection points.

  • The insulated tank houses the heated water until called on.
  • The heating elements heat the water and maintain desired temperature.
  • The thermostat allows you to control the temperature of the water. Most often 115 to 120 degrees.
  • The pressure relief valve is a safety device which is designed to open and relieve pressure in the event of a malfunction.
  • The drain cock allows the water heater to be drained for service and maintenance.
  • The electrical connections are connected to your homes service to power the unit.
  • The plumbing connections connect to your home's water supply.

Water Heater Safety

Before inspecting, troubleshooting or servicing a water heater, you must turn off the power at the main circuit breaker. As an additional precaution, you should also utilize a voltage meter and test all wiring connections to the water heater to verify power to the unit is off.

Unit Fails to Produce Hot Water

Water coming out of a showerhead

When your water heater fails to produce any hot water, it could be that the circuit breaker has tripped, the water heaters high-temperature switch has tripped, or you have one or more faulty heating elements.

  • Verify the breaker is in the on position. If it is tripped, reset the breaker to restore power to the unit.
  • Reset the high-temperature switch on the water heater. The switch is located behind the heating element access panels on the side of the unit. Be sure to turn off the power to the water heater before attempting this step.
  • Test and replace any faulty heating elements.

Lukewarm Water

Several circumstances can cause your water heater to provide only lukewarm water.

  • Hot water demand exceeds the capacity of the water heater. For example, running the dishwasher and using one or two showers at the same time could result in limited or lukewarm water.
  • One or both of the unit’s heating elements are faulty. A constant supply of lukewarm water usually points to a failing upper heating element. If your water runs hot for just a short time then cools, it usually points to a faulty lower heating element.

Water Leaks

Plumbing in a basement

Aside from safety concerns of a leaky water heater, it can also cause extensive water damage to your home. The three most common causes of a leaking water heater are:

  • Loose plumbing connections. Your home’s plumbing connects directly to the water heater. A cold water line allows fresh water to enter the water heater tank. A hot water lines allows heated water to leave the tank and travel to the area “a faucet” of the home that is calling for it. Inspect these plumbing connections for leaks and make necessary repairs.
  • Loose heating elements. The heating elements thread into the side of the water heater tank. Both are fitted with a rubber washer to prevent leaks. Over time, the washers can deteriorate, loosening the element and/or allowing a leak to occur. Inspect the rubber gaskets and replace when necessary. A water heater element wrench, available at most hardware stores, will be necessary to tighten and/or remove the heating elements.
  • A failing water heater tank. Water heater tanks are manufactured with steel. Over time, the tank will succumb to corrosion. As the tank rusts, it will eventually develop a leak that will increase as time passes. If your water heater tank has developed a leak, unfortunately, it is time to replace the entire unit.

Safety Warning

Avoid severe injury, death, or extensive water damage to your home. Without a strong skill set in electrical and plumbing repairs, it is recommended you leave this job to experienced and licensed professionals.