Electric Water Heater: Why does the temperature of my hot water fluctuate?
In an electric water heater, the upper and lower thermostats must fit snug against the side of the tank to sense and regulate the temperature correctly. Turn off the power to the water heater and remove the access covers to check the thermostats' positions. Adjust the thermostat brackets if necessary to keep the thermostats snug against the tank.
A failed thermostat or heating element in an electric water heater can also cause hot water temperature fluctuations. If water temperature fluctuates below the set temperature, check for failed heating elements and thermostats. If the water heater tends to overheat the water, find the cause of overheating. Replace any failed thermostats and broken heating elements.
Sediment build-up at the bottom of the tank can cause hot water temperature fluctuations. If it's been more than a year since you drained sediment from your water heater tank, now's the time to clear sediment from the tank. A broken dip tube that carries cold supply water to the bottom of the tank will cause temperature fluctuations. Replace the dip tube if broken. Some water heaters don't have a replaceable dip tube. If you can't replace the dip tube, replace the entire water heater.
THESE REPAIRS MAY HELP SOLVE YOUR ELECTRIC WATER HEATER PROBLEM
Replace the water heater heating element
The heating element is the heat source inside an electric water heater. It extends directly into the tank, where it radiates heat energy to the water around it. If the heating element is not heating when activated, replace the heating element.
Water heater heating element
How to replace a water heater element
If your electric water heater runs out of hot water quickly, or if the water isn't as hot as it should be, the heating element could be the problem. This step-by-step repair guide and video show how to replace a water heater heating element.
Replace the water heater thermostat
The thermostat constantly monitors water temperature in the tank. When the water temperature drops beneath the desired setting, the thermostat sends power to the electric heating element or gas burner to begin heating. If the thermostat isn't sending power to the heating element, replace the thermostat. In a gas water heater, replace the gas control assembly that contains the thermostat.
Water heater thermostat
How to replace an electric water heater thermostat
If your electric water heater makes the water too hot or not hot enough, the thermostat could be broken. This DIY repair guide and video show how to replace an electric water heater thermostat.
Replace the water heater drain valve
The drain valve threads into the bottom side of the tank and is opened to drain and flush out sediment from inside the tank. Replace the drain valve if it leaks or won't open to drain the tank.
Water heater drain valve
How to replace a water heater drain valve
If your water heater is leaking from the drain valve, follow the 6 quick steps in this DIY repair guide and video to replace the drain valve.
Most common symptoms to help you fix your water heaters
Choose a symptom to see related water heater repairs.
Main causes: lack of power, no gas supply, thermostat limit switch tripped, bad element, bad thermostat, gas valve failu…
Main causes: thermostats need adjustment, water heater capacity too low, bad heating element, thermostat failure, excess…
Main causes: loose water pipe fittings, leaky drain valve, bad temperature-pressure relief valve, leaky heating element,…
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Main causes: broken heating element, thermostat failure, excessive tank sediment, tank size too small, burner valve asse…
Main causes: thermostat temperature set too high, thermostats need adjustment, faulty thermostat, shorted heating elemen…
Main causes: faulty pressure relief valve, water is overheating…
Repair guides for electric water heaters
How to replace a water heater element
If your water heater runs out of hot water quickly and one of the two heating elements has failed, replace the element f…
How to replace an electric water heater thermostat
If the water temperature fluctuates or you don't get enough hot water, follow these instructions to replace your water h…
How to replace a water heater temperature and pressure (T&P) relief valve
Replace a broken temperature/pressure (T&P) relief valve on an electric water heater using these instructions.…
Effective articles & videos to help repair your water heaters
Use the advice and tips in these articles and videos to get the most out of your water heater.
Learn some of the most common symbols found in a wiring diagram and what they mean.…
Find out what’s wrong with your appliance by following a circuit.…
Read about some water heater repairs that you can easily do yourself.…