What is this plumbing part on Montana 3811MS

[sonofcy]

I have a plumbing valve under the sink of my 2018 Montana 3811MS and I do not know what it is for. Anybody know?

[Laredo240MK2015]

It sure looks like the water heater bypass valve. You use it to isolate the water heater when winterizing.

[sonofcy]

Thanks, but I don't think so, I have a special marked valve for that.

[JRTJH]

If you have an ice maker for your refrigerator, that is the water cutoff for that device. In the Keystone owner's manual is a drawing that details exactly how the ice maker water supply is routed through the floor and out to the slide and then back into the coach interior. The diagram is on page 42 in the Owner's Manual that I have. Pay close attention to winter use of the ice maker. The exposed water line under the slide is not protected from the cold and can cause some significant damage if it freezes and thaws. Turning off the water supply at the valve in your picture is a part of winterizing your ice maker.

[sonofcy]

BINGO. Note to self, RTFM. I knew there was a shutoff, but not 2. The valve closest to the fridge was leaking which is why we were looking at the plumbing in general. Now I need to find that third (low point valve) and open it as we will never use the icemaker for a few reasons.