Hot water tank, both pipes hot

It's obvious - you're a lousy plumber. ;)

The hot water is flowing backwards because the tank was mounted upside down.

You need the unions or maybe they are couplings that insulate on both pipes at the tank, I think.

I give....

cuz water heater is completely filled with hot water? And the heat from the water conducts out through both the hot & cold piping?

don't keep us in suspense too long

cheers Bob

Run the hot water for a second and the cold pipe will get cold. Heat rises and a sitting tank is bound to have hot water rise in the cold pipe by convection. Also the pipe inside the tank that brings the cold water to the bottom of the tank may be broken off.

Nope, water was running. Hint: that helped make it hot

Normally, the outlet is hot when running water and the inlet is made cold by hte incoking water. This is, though, an indirect fired water tank. Having used enough hot water to trip the thermostat, the heating sycle started so water was passing through the heat exchanger and back into the storage tank, already heated. Only during the actual heating cycle do you have both pipes hot.

You have a recirculating system?

Wayne

What are you talking about? The heat exchanger on an indirect is a loop into the boiler, not the potable water. The only way your scenario would be true, is if the potable water went through a coil in the boiler before it went to the domestic cold inlet on the indirect. Without anyone knowing what type of system you have and how it's set up, any answer could only be a wag.

Because the man was too short to reach the elevator button to the 20th floor.

Oh, sorry. Right answer, wrong question.

Broken or missing dip tube does some strange things.

Your answer is a wag. A wrong wag. True that some indirect fired systems have an internal coil for exchange in the tank, but mine has an external plate exchanger on the boiler. As stated, both top pipes are hot when using and making hot water. That was the "mystery" compared to a regular stand alone heater. There is a third pipe at the bottom of the tank too to complete the loop.

And anyone would know that you have some type of hybid system, because???

In a standard tank I am correct. You need to better explain your setup if you have a clue.

The purpose of me asking was to see if anyone could figure out it was not a standard tank. Sorry that went over your head.

Well I"m glad you could figure that out. Sorry for the lighthearted attempt at stumping people with a non-standard tank. Seems as thought at was lost on you and Count Chocula