Electric water heaters use, you guessed it- electricity, to heat the water. If your electric water heater isn’t working the first thing to do is check your breaker or fuse box. Many electric water heaters also have a separate disconnect box at the water heater, check this too.
If you are sure you have power, the problem is either your heating elements or thermostats. Most electric water heaters have two of each, upper and lower.
Turn Off The Power
In order to check or replace a water heater element you will have to turn off the breaker serving the water heater circuit and remove the access cover on the water heater. At this point you might get lucky and find the easiest way to fix an electric water heater.
Check The Reset Button
Many thermostats have a reset button which can sometimes be pushed to reset the circuit and get the water heater working again. To find it you may have to carefully remove any insulation covering the thermostat. If the reset button has been tripped you should be able to hear and feel a definite click when you push it. If you think it was tripped, put everything back together, turn the power on and check for hot water in about an hour.
Check The Elements
If the thermostat can’t be reset you will need a voltage meter or continuity tester before going any further. There’s not room in one article to cover electrical diagnostics but you can perform a simple continuity check on the elements to make sure they make a complete circuit.
Make Sure The Electricity Is Off!
First, make sure the power is off to the water heater! Then locate the heating elements. The elements will have two wires connected to each one and will either have a big hex nut where they screw into the tank or will be fastened to the tank with a bracket and usually 4 bolts. After confirming that the power is indeed off to the water heater, remove the 2 wires from the element and check for continuity. If there is not an intact circuit between the two terminals on the element, it is bad.
Replacing Bad Heating Elements
If one or both of the elements is bad it is probably a good idea to just replace them both. You will need to shut off the water and drain the water heater to replace the elements. If they are the hex nut style, you may need a special socket. You can usually find these tools where you buy the elements. Make sure the water heater is completely full and all air bled from the system before turning the power back on or you will ruin the new elements by “dry firing” them.
It May BE The Thermostats
If the elements are OK and don’t need to be replaced, it is probably the thermostat(s). It is a good idea to replace both thermostats if there are two, they are fairly inexpensive. Just remove the wires, connect the new one the same as the old one, put the access plate back on and turn the power back on. You should have hot water in about an hour.
This Is Not For Everyone, It Can Be Dangerous
Learning how to troubleshoot electric water heaters can be fairly simple but you do need to understand and be comfortable working with electricity. It can literally kill you if you fail to observe the proper safety precautions. If you aren’t qualified or aren’t sure about something, call a professional. It is better to be safe than sorry.
This article is for information purposes only and in no way should be interpreted as an encouragement to attempt any repairs for which you are not qualified. I accept no responsibility if you try something beyond your capabilities and something goes wrong.
Copyright 2008 Bryan Stevens