Electric Water Heater Repair and Troubleshooting (2024)

No Hot Water

It may take several hours for a newly installed electric waterheater to reach normal operating temperature. If you don't have hotwater after two hours (water not even warm), first check to makesure the water heater is getting electrical power. Not gettingpower is a common reason new water heaters don't work.

Checking for Electrical Power

You can check for power with a simple "circuit tester," but fora more complete diagnosis of electrical problems, you'll need ameter that measures voltage.

To check for power, turn the circuit breaker marked "waterheater" off (or remove fuses). Remove the water heater's upperaccess panel. Carefully remove the insulation and plastic cover.Identify the power supply wires. Usually, these connect to the toptwo screws of the upper thermostat. Turn the circuit breaker backon and check for voltage on the top two screws of the upperthermostat.

The label on the water heater indicates what voltage the waterheater requires. Most residential units are 220/240 volts (but someare 110/120 volts). Verify your water heater is getting the correctvoltage. If it is not getting the required voltage, there areprobably issues with your home's electrical system. A qualifiedelectrician may be needed to fix your electrical problem. Turn thecircuit breaker off, replace the plastic cover, insulation andaccess panel.

Testing Thermostat for Power with Voltmeter

If the unit is powered with the correct voltage, and still doesnot produce any hot water, the upper heating element has probablyburned out. A water heater must be completely full of water beforeelectric power is applied or the upper heating element will burnout (this is called Dry Fire). The Installation Instructionsrequire that a hot water faucet be opened and the hot water allowedto run full for at least three minutes before turning the power on.This is to make sure all of the air has been removed from the tank,and the tank is completely full of water. If the upper element hasburned out, it can be replaced. Replacement heating elements areinexpensive and widely available. After the heating element hasbeen replaced, make sure the tank is completely full of waterbefore turning the power back on.

Some Hot Water, but Not Enough (New Installation)

If a new water heater produces some hot water, but not as muchas you're used to or not as much as you need, the thermostats mayneed adjusting. The Installation Manual has temperature adjustmentinstructions for your unit as well as important safety informationabout scalding. Water heater manufacturers recommend a temperaturesetting of no higher than 120ºF. Higher temperatures increase therisk of scalding injuries. Read and follow the temperatureadjustment instructions and safety notices in the InstallationManual that came with your new water heater. Remember, highertemperatures (above 120ºF) can cause serious injuries.

Another possibility is that the water heater is not getting thecorrect voltage (see Checking for Electrical Power above).It is also possible that the water heater is too small or that yourusage has increased.

Water Leaks

With a new water heater, most leaks are caused by leakingconnections at the hot water outlet or cold water inlet.Occasionally, leaks can be found coming from a fitting (such asaround the Temperature and Pressure Relief Valve) or around one ofthe heating elements. Leaking fittings can often be tightened orrepaired. It is extremely rare for a new tank to leak.

Water Drips

If drips are noticed coming from the discharge pipe of theTemperature and Pressure Relief Valve, the home's water pressuremay be too high or a thermal expansion tank may be needed.

Note - If large quantities of hotwater are coming from the discharge pipe, turn electrical power offand consult a qualified technician. Do not cap or plug thedischarge pipe.

Water Pressure

Check your home's water pressure with a gauge. The recommendedwater pressure is 50 to 60 PSIG. If the pressure is higher thanthat, install a Pressure Regulating Valve (or adjust your existingpressure regulating valve if you have one). For water pressureissues, consult your local water utility or a qualified plumber.Most plumbing codes require a Pressure Regulating Valve if thewater pressure is above 80 PSIG.

Thermal Expansion Tank

When water is heated, it expands. In older homes, the expandedwater pushed back into the water main. Today, most homes havebackflow prevention valves which stop the water in your home fromreentering the water supply. These valves can be inside watersofteners, pressure regulating valves or the water meter itself.Backflow prevention valves (also known as "check valves") preventthe expanded water from reentering the water main. Since theexpanded water now has nowhere to go, the water pressure in thehouse's pipes can increase dramatically, often to the point wherethe Temperature and Pressure Relief Valve discharge pipe drips. Athermal expansion tank has an internal air bladder which can absorbthe expanded water, protecting plumbing, appliances and the waterheater. For these reasons, most homes now need a thermal expansiontank (and a properly adjusted pressure regulating valve). Nothaving a thermal expansion tank is the most common reason for adripping discharge pipe.