New water heater problem!

adambuild

Last week installed an AO Smith Model # XCV 50 100, 50-gallon water heater to replace same in a residential app and they run out of hot water after about 20 minutesd of "regular" usage!? We don't sweat near the dip tube. Any other thoughts? When I was there last week, the water was 125* at the laundry sink next to it. It's happening at all fixtures. I initially thought cold was migrating to hot side but doesn't seem to be. Any ideas? First time it's happened in all the years!

Thanks in advance, Adam

ed wallace

running out of hot water

I would check the dip tube

[Deleted User]

Got circ return???

If you have one without an operational check valve, it too can create a situation that mimics running out of hot water.

ME

heating tech

you could have a defective dip tube, possibly a bad unitrol did you let the tank fully satisfy and then turn on the hot water, if they dont get enough you have a cracked dip tube which will not give you enough hot water. if its happening in more then 1 area its a tank problem.

Larry Weingarten

Agree...

... with the others. Dip tube, cross connection, or recirc line. The dip tube could have been put in the wrong side, or simply not installed. A cross connection shouldn't happen at the same time, but it could be something as simple as a shut off valve on the shower, downstream of the hot and cold valves. If there is not a working check valve in a recirc line, you will get backflow. I prefer spring check valves over swing checks in my hard water area.

Be curious to know what you find.

Yours, Larry

martin

Low hot water

I had something similiar happen to me several years ago. Cold water was leaking thru a moen single handle shower valve and diluting the hot.The valve was closed and didn't leak but would bleed thru. Shut the input valve to the heater and turn on a hot spigot at the lav if you have any water other than gravity that could be the problem.