Hot Water heater acting strange

Hello everyone!! I think I know what is wrong but want to run it by you guys.

I have an American PROLine water heater 80 gallon circa late 2002 begin use 2003. Electric with two elements.

Last couple days my wife was complaining of overly hot water. I use a thermostat to take temp and it is 135F. This is warmer than normal but not scalding. Shower feels hot, water at kitchen sink feels hot. I go to the thermostats at the water heater and dial them back from just over 125 to just under 125. Wait a half hour, take a shower and retest water in kitchen which reads 122F. Better..... and I go to work.

Come home and my wife now says water is cold. Go back and check thermostats and breakers, this is what I get.

I immediately notice it does not seem to be running. The top thermostat has a red push reset button. I push it and it snaps. WH starts making faint noise, barely discernible. I get the multireader and the top element reads 240V and the bottom element reads 120V exactly. I think wait a minute, 120??? Well, I guess it seems right. Ten minutes later I hear a "click" and the WH really cranks up now I can really hear it heating up the water. Go to recheck the volts and I get 000 on top and 240V on bottom. Red reset button is NOT tripped.

Any ideas besides bad thermostats? This is my guess...
Why is the top element not reading anything when it was 240 just a minute ago?
OKAY to use the breaker to control it until I get it fixed?

Replacing thermostats on a WH a DIY job? Should I go ahead and replace elements too? That a DIY job? Should I chuck it and get a new one because it is 12 years old? My water is city water hard.

Both elements don't heat at the same time. Once the top of the tank warms up, power is sent to the bottom element.

Before digging into repairs on this one, price out a new unit. Water heaters can have a short life if the water is anything but perfect. And newer units are generally more efficient.

Electric Water Heater Elements Diagnosis

Multi-meter used for troubleshooting electrical issues
A multi-meter needed for the test

•First you need to check the breaker for the water heater. Make sure the breaker did not trip. In most breaker panels where the breaker is tripped it will show a red indicator next to the breaker. If the breaker is tripped for the water heater then try to reset the breaker. If the breaker trips after resetting you have an electrical problem. You will need a multi-meter that will read voltage and Ohms. Then you need to open the panel where the heating elements and thermostat are located. First check to make sure there is not voltage going to the heating elements or the thermostat. The wires coming into the water heater from the breaker panel are where you need to check the voltage. Using the multi-meter set to volts check the voltage. You should get zero volts. If you get zero volts then proceed to the next check. If you get voltage the breaker is not tripped and the breaker panel is probably labeled wrong and you need to call a professional.


Electric Water Heater Thermostat
Electric Water Heater Thermostat is a temperature switch that turns the elements on and off based on the temperature setting and tank temperature.

•Once you have confirmed there is no voltage going to the water heater (because of the tripped breaker you need to disconnect the wiring going to the water heater originating from the breaker panel. This is the main electrical connection to the water so it is very important you make sure the voltage reading is zero. Make sure you test each wire from one wire to the other and each wire to ground. The ground screw should be a green colored screw next to the wiring connections. Usually the connection method is done by wire nuts with the ground connected by a green colored screw. but other methods could be used to make the connection. Disconnect the wiring connection.

•Then find the heating elements – you should have two one in the top of the water heater and one near the bottom of the water heater – Take a photo
heating elements connections - no hot water of the wiring or make a drawing of it so you will know how to rewire it when you are finished. Once the wires are disconnected turn your multi-meter to Ohms. Ohm the connections by placing one lead on one connection and the other lead on the other connection. You should get somewhere between 10 Ohms to 24 Ohms depending on the wattage and voltage rating for the heating element. If you get a “0” zero reading on the Ohm meter the element is bad If you get infinity on the meter – the meter doesn’t respond – then the element is bad and needs to be replaced.
•repair and diagnosis of electrical issuesIf you find a bad heating element then you need to drain the water heater. Turn off the main water supply to the water heater before opening the drain valve on the bottom of the water heater.Then you will a special tool that most hardware stores carry specifically for this purpose along with a new water heater element. It is important that the new water heater element is matched according to the wattage and voltage for it to work properly. The hardware store should advise you of a proper replacement. Once you have replaced the bad element with the new replacement element restore all wiring to normal. Close the drain valve and turn the water source for the water back to the on position.

Restore the breaker to the normal position. You will have to wait until the water heater heats the water so you can take a shower or wash dishes but you made the fix and now it is only a matter of time before you have hot water again. Then everyone will be happy. Good luck!