Jayco hot water tank valve

[Slow and Steady]

On my new 2017 J Flight 29 RKS, I was looking at the atwood hot water tank under the counter between the sink and refig and I see only one value mounted on the front of the tank. I always have seen three valves on other rv tanks.

And now when I want to de winterize the water system, I am not sure which way to turn the valve to keep the hot water tank from getting any of the antifreeze into it. Their isn't any markings. Just one plastic valve on the front.
Does anyone know anything about this?

Thanks.
Tom and Kathy

[Hoppy220]

That should be a 3 way valve, installed in the "cold" water line, the handle should be in line with the supply line to fill hw tank and should turn 90* to line up with the cross over line to bypass. There should be a check valve in the hot water line coming out of the tank to stop the flow of antifreeze into the tank

[andrewat]

If it's like my setup (2017 27BHS), it's actually not a 3 way valve. There are only two. Not sure why they set it up that way. But you're probably right, there are not three for the bypass. I don't know how they would setup a bypass with one valve. So make sure there isn't another one hiding in there somewhere.

In any case, I have to turn both valves to bypass and it works.

[Hoppy220]

Originally Posted by andrewat

I don't know how they would setup a bypass with one valve.

Pretty simple actually, with a 3 way valve. In one position the valve allows water into the heater to be heated and exit out the hot side of the heater, turn the valve a quarter turn and the valve diverts the water out the 3rd line (the tank bypass) and there is a check valve on the hot side of the tank that won't allow water to back flow into it. Simple set up and only uses one valve and a check valve instead of 3 valves.