Hot Water Heater - Water Temp Lowers as Unit Sits

[Buddycot]

Hi all, we are dealing with an electric water heater. The issue is this...

After no draw from the tank for some time, we run hot water (enough for a shower or to fill the tub) and it is really warm but not as hot as the setting on the tank. Then, after about ten minutes of the tank refilling after use, if we turn on the hot water tap again the water is really hot.

The issue is that after the tank sits for awhile the water cools back down to this really warm temp. Is it a cold water mixing issue? Heater element? Thoughts?

Thanks!

 

[Jeff Handy]

Is there a tempering/mixing valve on the water heater?

Post a few pics of the plumbing connections on top of the heater.

And a pic showing brand and model number of the heater.

 

[Riickk]

Sounds normal to me, thermostat in tank has an upper and lower limit. Water will cool until lower limit reached, then heating elements cut in and raise temp to upper limit. You're experiencing lower-limit temperature.

Me, I just run hot only at vanity for a minute or so, 5-10 minutes before shower. Not exactly insta-hot, but it works.
Alternatively, raise the water temperature.... But, raise it too high, and you risk scalding

 

[Buddycot]

Is there a tempering/mixing valve on the water heater?

Post a few pics of the plumbing connections on top of the heater.

And a pic showing brand and model number of the heater.

Thank you for the reply. Here are a couple pictures. The unit is a GE PE50M09AAH, MFG Date 06/2011

 

[Buddycot]

Sounds normal to me, thermostat in tank has an upper and lower limit. Water will cool until lower limit reached, then heating elements cut in and raise temp to upper limit. You're experiencing lower-limit temperature.

Me, I just run hot only at vanity for a minute or so, 5-10 minutes before shower. Not exactly insta-hot, but it works.
Alternatively, raise the water temperature.... But, raise it too high, and you risk scalding

Interesting. However, it is never hot again after the initial reheat process. So I don't think it is ever reheating once lower temp is reached and the heating element is supposed to kick back in.

 

[Diehard]

I would first check the temperature settings on the 2 heating elements. Assuming they're both set at approx. 120 degrees F., I would then check if both are functioning.
There are many videos on how this is done. All you need is a multimeter.

 

[TomFOhio]

The bottom element is probably bad and you are heating water from the top element only.

 

[modet]

What's the doodad above the hot outlet that has wiring? Is that part of the temperature control for the heater? You don't seem to have much in the way of insulation on the hot pipes.

 

[SHEPLMBR]

What's the doodad above the hot outlet that has wiring? Is that part of the temperature control for the heater? You don't seem to have much in the way of insulation on the hot pipes.

It is probably acting as a junction box. Looks a bit shady.

 

[Jeff Handy]

It has hot water plumbed into it.

So maybe a thermostat for a circulator pump?

And yes, insulate the hot pipes, cheap and easy.

 

[SHEPLMBR]

or a timer for it.