: I have a 40 gallon Rheem electric hot water heater. Abruptly last week, my wife declared that there "was no hot water". So, up into the attic to have a look, the upper thermostat reset button was tripped, reset it and voila, hot water. Except that now, 3 days later, it has done it again.
: I have current running through the upper thermostat and heating element. I don't have any current running across the upper thermostat terminals that run to the lower thermostat (and, obviously, no current at the lower thermostat or heating element). However, I am unsure if I should always be able to measure current at the upper thermostat, or only when the lower element is actually supposed to be heating.
: After that long and sad tale, my question is: How do I know which part is bad - the upper thermostat, the lower thermostat, or the lower heating element? In reading some of the other posts here dealing with electric HWH issues, I have seen references to "continuity testing", but I have no idea what this means. My preference would be to have someone professional come and look at the unit, but I live in rural Louisiana, and getting someone to come out is not so easy.
: Any advice appreciated. Any solutions GREATLY appreciated.
Neal: continuity example--say you know you only have one power cable coming to your house and three bare wires are sticking out of the ground in front yard.You don't know if the are "hot" or not. They all look the same but you are wary of them. So you call your little brother over and say touch that first wire-he does and his hair start smoking, then when he recover a bit you say touch that second wire- little brother does it again and the hair smoke again, by this time little brother is catching on but you tell him touch wire number three,he look at you and you tell him it will be the last time and he can ride in you car if he do it. So he touch the last wire and no smoke, brother is smiling. You say to him now get away and don't bother me till I need you to test continuity again. To recap what you have learned , wire 1 and 2 have continuity. Wire 3 does not have continuity with either 1 or 2 . If you don't have a little brother around all the time you can buy a continuity tester at the auto parts store for a few bucks. It has two leads on it attached to a small battery and flashlight type bulb that will light up instead of the smoking hair method. Be sure to turn the power OFF when using this method as you are supplying the power with the small battery. You can also go to radio shack and buy a circuittester/ohm meter/voltage tester/continuity tester all rolled into a little box with two leads that will do the same thing, cost about 15 bucks as I recall (turn POWER OFF) except you read a dial that is powered by a little battery. Read the little instruction book and it will tell you how to use it. You will vastly improve your knowledge base and can then do your own checking . Just remember when in doubt-don't do it. In case you missed it do continuity testing with power off from breaker box. Hope this helps--bigbrother