I live in a house that was built in 2011. The water heater (AO SMITH, ECT 52 210). I noticed about a week ago the water was only warm, not hot. The wife called a plumber, he drained the water heater, and changed the lower element. NOTHING Changed with water temp. The next day he came back out, said the diagnostic checks out but changed the top thermostat anyway. Nothing changed. He said if it doesn't get hot, I need a new water heater. That didn't make sense to me, so I changed both thermostats and heating elements again, I also looked inside and saw the dip tube seemed to be in tact with no issues. The top of the water heater is actually getting to around 105 degrees, whereas the bottom DOES NOTHING and stays around 63 degrees. I caved and bought a new water heater.

The new water heater is a Rheem XEM50M12EC55U1. I installed it myself, but still have the same issue. It has a digital screen and tells me the temp of top and bottom. I set it to 125, but after about 6 hours the top temp is 107 and bottom 64.

I have checked my power going to the water heater. Each wire gives me 120v DC with the ground. I get 240 on the water heater.

I checked the house water pressure and have 80psi.

I NEED HELP!

 

That is baffling. There isn't much to a water heater just two thermostats and two heating elements. I would open a hot water tap inside the house or wait until someone has just taken a shower. This is to make sure the water heater is on and heating. Check the voltages at the water heater when it's heating. I'm curious if you are still getting 240 volts. The only thing I can think of is you have a power problem. It may show 240 volts at rest but might be dropping significantly when it's heating.

 

With a load (The water heater attempting to heat, It is still drawing around 240v DC.

 

Why is your testing device reading DC (Direct Current) ?

Isn't your circuitry AC ?

 

If it is not the water heater and it is not the voltage, it must be the current. Can you see anything with the wiring that might limit the current. A bad connection. A mouse eaten insulator. A cut in the wire of some sort.

In any event, if something is limiting the current, that power is most likely being lost as heat. Possibly a lot of heat and this type of situation is where electrical house fires come from.

I cannot think of anything else so I would be very concerned. That breaker would be off when I go to sleep tonight until I found out what is causing it. If the tank is in the basement perhaps the wiring is visible for you to follow along and look for defects. If it is in the walls, did anyone hang up a picture lately or add a big screen TV to the wall, that might have damaged a wire?

Hopefully someone else comes up with something so you can at least have 105 water but until then I strongly advise you to turn off that breaker unless you are in diagnostic mode at the time.

 

If you reduce/limit the available current the voltage will go down.

I would check for 240vAC directly on the elements.

 

SO....I found the cause. On another website an individual told me to test water pressure with water main on, then turn it off. Come to find out I have a water Leak. I narrowed it down to a hot water leak under the foundation near a bathroom and master bedroom. I am now putting a lot of things together, and I DO believe the leak has been there for at least 6 months....just now got real bad.

 

Heating that much hot water should have presented you with a massive electric bill.