So my water heater started leaking on Christmas morning... It is only 6 years old. After doing some investigating, I found that the cold water supply was the part leaking. Here's my question... If you look at the pictures below you will see a regulator valve (??) on the inlet side after the cut-off valve, but before the tank. It has a twist dial, presumably to adjust the allowable pressure. The pipe that extends out the top and then 90's down just points down to the drain pan on the floor. I believe it is this valve leaking. After about an hour on the internet, I have not seen any installations with this adjustment regulator. Does anyone recognize this? Is it necessary? Just to be clear, I'm not talking about the TPR valve. I know what that is for.
On a separate, but related, topic the pan is not draining (which is how I found the leak). The water heater is located near one of my air handlers. Is it possible the drains are plumbed together? The house was built in 2005 and is located in Florida.