What is it?
Hot water circulating pump with timer. Typically located at most remote fixture.
That is a Instant Hot Water Circulator. Did the home have wood floors?
Yes it had wood floors but this was located about two feet from the water heater.
Why would it be right next to the water heater?
They can be plumbed that way too. Look for a crossover at the remote fixture or a separate return line coming off the hot side.
Yep, thanks Michael.
How about the exhaust setup in the HVAC thread? You ever seen it that way?
The main reason for one of these is for forced, quick hot water to whatever faucet its aimed at…supposedly bypassing the warm up stage of water going to a hot water faucet…
That makes perfect sense. This was a one story home converting to three. Thanks for the links. Just what I needed.