Newbie: Valve in Water System

[Tinbagel]

I'm a new owner of a 2015 MBS 24R and am winterizing for the first time. I think I have everything completed but in the process I came across this valve and I'm wondering what it is for.

[backdoctor]

That is the valve to dump the water in your fresh water storage.

[Tinbagel]

A little confused: Don't the low point drains do this? I used that method and when I opened the pictured valve nothing came out.

[Scrapper]

If that's your FW tank in the background, it still has quite a lot of water in it.

[Asrabbit]

The fresh water tank has a drain that is separate from the low point drains. Water would only come out when this valve is opened if you had water in your tank. If there is no water in the tank, then nothing will come out when you open the valve.

[rockfordroo]

There is a pump and a check valve, and most likely a 2-way or a 3-way valve, between your main cold water plumbing and your FW tank. And you can see your pump is higher than the bottom of the FW tank. So the low point drains only drain the main plumbing (and not necessarily all of it, depending on it's ups and downs). So the FW tank has its own drain.