This article was originally published on DoItYourself.com.
If you're used to taking hot showers in your mobile home, then stepping in one day to find that your water is consistently lukewarm or ice-cold might be a rude awakening. If that happens, you should test your electric water heating element. Towel off, and head to the breaker panel with a screwdriver and two meter probes handy.
Many small appliances contain heating elements, which are simply pieces of metal wire that resist a controlled electric current to creating heat. The heat stemming from the wires is what your water heater uses to warm your water. If your heating element is broken, it isn't properly converting the electricity flowing to its wires into heat. Heating elements are fairly easy to test and repair; however, you should only attempt either if you are knowledgeable about working with electricity.
Find the switch that gives your water heater power, and shut it off. Use the screwdriver to remove the cover(s) (there are usually up to two) over the thermostats and elements. At this point, you should see plastic shields over the element connections – carefully snap these off. You need to be absolutely sure that you don't electrocute yourself, so double-check that you have successfully turned off the water heater's power by setting your meter probe to “volts” and gently touching the probe to the element's screws.
At this point, one of two things should happen: your meter should beep, or its needle should sway way over to the side. If you find that neither of these things happens, then there is no power, and your meter settings are incorrect. Changing your meter setting to “ohms” or “resistance” until you hear a beep or see the needle jump should solve the problem.
At this point, carefully remove the two wires connected to the element. If you're not sure which part of the water heater is the element, keep in mind that most elements are small, rectangular-shaped boxes with screws installed along their edges and two different-colored knobs/buttons at opposite ends. Gently touch the heating element's screws with your meter probe.
Now that you know your meter is working properly, the results from the test should be trustworthy. If the meter beeps or the needle sways to the far side, then your heating element is in fine working condition, and the problem may potentially be caused by a dysfunctional thermostat, which is a whole other can of worms. If your meter does not beep or the needle only moves a tiny bit, it's time to replace your malfunctioning heating element.