Valve on Overflow

[spike43]

I have a 2011 321RLTS 5er and want to add a valve on the freshwater overflow.

When I looked at it this weekend, there is a 1/2 inch pipe (overflow I believe) and next to it there is another pipe about 2-3 inches diameter. What is it for?

Thanks

[SMS1115]

On my tank I have 2 overflow hoses about 1/2" diameter and a country fill hose about 1 1/2" diameter and the pump suction about 1/2" diameter. On the bottom of the tank I have a valve that looks like a hose bib for your house that is the tank low point drain.

[barryg]

While I have a 2016 eagle ht unit as opposed to yours I have what sounds like the same hose setup. If I over fill my tank it comes out the large hose (on ours it is not a pipe but a 2ish inch flexible/collapsible hose). The reason I think it is the overflow is two fold one that is the hose that flows water out once full but also if it was the smaller hose it could not keep up with water intake at pressure so while it would let water out it wouldn't be as fast as the water going in under pressure. I am thinking the small hose is the vent. My low point drain is a few feet farther back at the rear bumper with a valve. I have an issue that if the large hose starts flowing I let it run for a minute then clamp it off to get it to stop flowing then slowly open it up so it doesn't start to siphon (which is why I let it run for a minute before clamping it off) . I have thought about putting a valve on it but just haven't done it yet since I will have to convert from 2 inch flexible to a hard pipe with a valve. Should be an easy thing to do just haven't done it. Tired of getting to a dry campsite with 1/3 of a tank of water after filling it at home just to have it siphon out on the way.

[JFlightRisk]

Not exactly the same unit, but this is what we added to the overflows. We have two fresh water tanks.