Hey guys.

My neighbor got talked into replacing his big tank water heater with a tankless. Now he is unhappy with the lack of hot water in his master bedroom shower, which is as far from the tank as any other hot water tap. Strangely, the bathroom that is adjacent to it has no issues.

I was wondering if there is a recirculation pump that could be installed, that with the push of a switch, would push the cold water back to the tankless and draw hot until the temp rises enough.

Here is the thing. His bathrooms are just lousy with tile, and there is no cutting of walls. The house is on a slab and the supply is in the attic.

Is it a violation to put the pump in the attic above his shower? I know there is an electrical junction box up there with ample ampacity to drive a pump.

If anyone could point me to a particular pump or three, I'd certainly appreciate it.