Sometimes I'm left scratching my head . .

[WaltBennett]

Brilliant me forgot and left the cap to the fresh water drain on the edging to our driveway last fall when winterizing. A couple weeks later, when I remembered what I'd done, I couldn't find it anywhere. We'd had a few fall storms, so I figured the wind had just made off with it. Some time later when I was near an RV place, I picked up a couple of those little white caps. Finally got around to de-winterizing last week and found that the little white caps (same as for the low point drains) don't work on my fresh water drain! Took a photo of it and went back to the RV place (a Tiffin and SOB dealer). Parts person said she'd never seen anything like it before. She asked: "Why didn't I have the same fitting as on the low point drain?" All I could say is that Keystone made it.

Turned out the strange fitting is 1/2" in size instead of 3/8" and I found caps at the local Lowe's. Couldn't find anything looking like the fitting itself there, but at least I can fill the fresh tank now. Think I'm going to find a nice sturdy valve and put it on instead. Just another thing to do, but WHY two different sized fittings?

[BB_TX]

Being larger I can only surmise that the larger pipe is to speed draining of the fresh water tank. I know when full or near full mine takes a long time to drain. My low point drains do not have caps. They have valves in the convenience center.

[PackerFan]

Don't keep scratching your head over this one....That's why our hair keeps getting thinner as we get older!!

[DQDick]

Only one of the reason I replace the cap with a valve. Now when I drain nothing leaves the fitting.

[Mudchief]

I also replaced with a valve.

[Slink]

Is air breathing vent clean at fresh water fill how much water is in the tank is the trl level