Inadequate supply hot water

[jsurow]

My 50 gallon A.O. Smith Proline electric water heater, only three years old, has a very limited supply of hot water. After one shower water is only warm. At the kitchen sink before a shower I measured the temperature is 118°. After the shower I measured the temperature in the shower at 101°.
I turned off the water heater and drain the water from its brain, initially 80° or so. After perhaps 10 gallons the temperature went up to 120°.

The impedance across the upper thermostat is 0 ohms when turned all the way hot, and 25 ohms when set to 120 degrees. the impedance across the lower thermostat is always zero ohms, whether turned up or down the maximum.
The resistance across both the upper and lower heating elements is about 22ohms.
The voltage across the both heating element is 0 when at temperature, but 220 V when the temperature is raised and heating is heard in the tank. When the temperature set is adjusted by me, the lower thermostat seemingly "clicks" on at a higher temperature than the lower.
I'm not sure what's wrong. SHouldn't the water in the bottom of the tank, near the start of draining, be much warmer than 80°? Is the problem likely that the setpoint of the lower thermostat is incorrect and that it's not coming on to warm up the water in the bottom of the tank until it's very cold?
What do you recommend doing?

 

[Twowaxhack]

call a professional or look up how to test water heaters with a multimeter. Be careful.

 

[sarg]

One of dozens of videos .......... usually a simple continuity test is all that's required ........ and your described issue is usually the bottom element has failed so only the top portion of the tank is heating. And just a couple suggestions >>>> while the bottom element is out look inside the tank with a flashlight to see if the bottom of the tank is full of sediment ( can be removed with a wet vac and length of pliable auto heater hose attached ) and also check the condition of the anode rod.

 

[Twowaxhack]

I like to check amp draw of my elements while they’re heating.

Continuity check doesn’t cover all your bases. The element can still have continuity but be heating at a much lower rate.

A water heater element can also be grounded out to the tank and still heat continuously causing a high temp situation before it fails.......even with the thermostat not calling for heat.

The Upper thermostats ECO usually activates when this occurs.

If the upper ECO fails your T&P valve hopefully operates.

If it the T&P fails to operate and it’s a closed system........and continues to heat.....You have a dangerous situation.

 

[sarg]

Or ... if you have less patience ......... just replace the bottom element for $10. The probability of success is in your favor.

 

[Twowaxhack]

Voltage should never be Zero at the element.......

Each element is supplied 120v at all times.

Touch one probe to ground (the bare tank) and recheck to your element screw terminals.

The thermostat is the switch that supplies the other 120v. when calling for heat.