I have a 40 gallon electric water heater that only provides a small amount of hot water before the water temperature goes cold. Could the problem be one of the elements or perhaps the upper or lower thermostat?

Though I'm not a plumber, I have had this happen to me and it was the "cold water dip tube" that needed to be replaced... Easily replaced by a plumber in less then an hour for about $130 (in my neck of the woods), but I understand that a handy person can also do it themselves...

Could be one or all of your examples or what One 4 A says too. You will need to check the electrical part with a VOM and the only way to check dip tube is to remove the top heating element and look inside for it. Easy fix in most cases.

I guess another question to answer.. How old is the unit?

Hi all

You always start with electrical tests on electric water heaters.

First, always start by testing your electrical tester in a working outlet or similar to be sure it is working properly. Test electrical tester.

Then, check voltage into the heater junction box... should be getting 110-120 volts at each leg of power (220-240 volts total) for a 40 gallon electric water heater... if you don't how to do this stop now and call a qualified plumber or an electrician. If power is missing to one of the legs then the circuit breaker back at the electrical panel is probably defective and needs to be replaced.

Next, easiest thing to check is the elements. Here, you shut the power off to the water heater... then CONFIRM power is off using your tester... then remove the two wires from the upper and the lower elements. Now, you can do a continuity test using an electrical tester. Here, set the tester to read continuity and put one lead on each screw of the element being tested. If no continuity then that element needs to be replaced. If continuity is found then proceed to test the last element (you can also do an OHMS test, but I never do it this way). If continuity is present there then on to the thermostats.

In terms of the termostats, you are simply best to replace the upper and lower thermostats as they only cost $10.00 each and troubleshooting them is almost impossible... especially trying to explain over the internet... ;)

Finally, if these steps do not resolve your issue you can look at the dip tube, but only as a last step as this is the most involved for the homeowner to do by themselves.

More questions? Let us know, OK?

Mark