Fresh Water Tank Drain Ball Valve Replacement - 2015 Phaeton

[vettenuts]

I have a small leak through the ball of my fresh water tank drain valve. I don’t believe that the ball/seat is repairable. I could add a pipe plug to the end of the drain pipe but prefer to replace the valve itself.

It appears the better approach may be with a heat gun, but the fittings are in a very tight spot and I don’t want to damage any of the tank fittings.

Has anyone successfully replaced this valve that can offer some recommendations.

[edge68474]

Following. Thank you.

[windfall96]

I'd be careful using a heat gun for fear of damaging the tank. My drain has a screwed which connects to the tank and then a pvc screwed pvc adapter, short pipe, valve, short pvc pie then elbow /pipeexiting coach. So once you cut the pvc it should just unthread from tank. Is yours different. See photo.

[vettenuts]

Mine is similar, but the tank threaded fitting is plastic but there is much less exposed pipe as the valve almost touches the tank. I was hoping someone had done this and knew how easily that fitting unscrews from the tank. Once the tank is messed up, I am basically screwed.

[thegats1]

Originally Posted by vettenuts

Mine is similar, but the tank threaded fitting is plastic but there is much less exposed pipe as the valve almost touches the tank. I was hoping someone had done this and knew how easily that fitting unscrews from the tank. Once the tank is messed up, I am basically screwed.

Do you have a picture?

[vettenuts]

Just took one

[thegats1]

OK, I don't know your skill level, so please don't be offended if I am telling you something you may think is obvious. I'm not a plumber, but have replaced many pvc valves/fittings over the years. It appears to me you will need to make 2 cuts on the 2 glued ports of the side out elbow (the 3 port fitting). After cutting, can screw the fitting off the connection to the blue drain line. You can also unscrew the fitting to the tank. It does appear to be threaded and designed to be removed from the tank outlet. I can't see undere the cabinet floor there, but if it is like mine, it is only the pipe dropping below with no fittings. Anyway, then just buy the exact same parts, some purple cleaner, some pvc glue, teflon tape for the threaded fittings, and put it all back together. Of course you will need to put the threaded fittinngs together first. As you pointed out, just be careful removing the fitting to the tank. Looks like you can put some channel locks up against the tank outlet piece coming out of the tank to prevent turning it out or breaking it. Of course I would use something soft between the channel locks and the tank fitting to avoid tearing it up. I have a small miniature sawzall I use for cutting things like pvc using fine tooth blades (same blades I use for metal cutting). I hope I didn't confuse you any. Good luck!

Edit: your plug idea at the bottom sounds like a better idea to me. But each person's tolerance is different.

[garykk]

Originally Posted by vettenuts

Just took one

Attachment 390910

I use a PVC cutter now instead of trying to cut the pipes with a saw. . A lot cleaner and quicker. Looks like you just have to cut the bottom drain pipe off at the shut off fitting, unscrew the fitting on the blue water line and then use the remainder to unscrew from the tank. But as you said, kind of scary removing it from the tank without messing up the tank. Hopefully it’s just soft sealant that Tiffin used. You’ll just need to buy the replacement parts plus a length of PVC pipe.

[BradS]

I suspected a leaky valve (like you) and capped the drain pipe. Now I'm suspecting the threaded connection to the tank and NOT the valve. I think the repair will be the same.

I found the hole in the wet bay floor to not line up with the drain pipe. So when driving this misalignment was pushing the threaded connection sideways... leading to my leak. I haven't fixed mine yet, since it's just dripping now. I did enlarge the hole in the floor to relieve the side pressure. When I fix this, I will add a hose thread to the drain pipe to allow draining to a more remote location

Hope this helps..

[vettenuts]

Thanks for all the responses.

I can actually feel the water inside the pipe so in my case I’m pretty sure it’s the valve itself. Like yours, mine is also a tight fit to the through hole in the floor of the bay. I am now in Red Bay, which was a trip originally planned for other reasons, but I am going to have them change out the valve.

In a house, I wouldn’t hesitate to replace the fitting assembly. However, I remain concerned because I don’t know how Tiffin installed the threaded fitting and don’t want to risk the tank spun weld connection. I have found other plumbing fittings that have had a sticky sealer that requires a lot of force to overcome. In normal plumbing, these same fittings wouldn’t have a sealer so I can only assume they used these sealers to prevent leaks due to over the road vibration.

[BobGed]

Originally Posted by vettenuts

Thanks for all the responses.

I can actually feel the water inside the pipe so in my case I’m pretty sure it’s the valve itself. Like yours, mine is also a tight fit to the through hole in the floor of the bay. I am now in Red Bay, which was a trip originally planned for other reasons, but I am going to have them change out the valve.

In a house, I wouldn’t hesitate to replace the fitting assembly. However, I remain concerned because I don’t know how Tiffin installed the threaded fitting and don’t want to risk the tank spun weld connection. I have found other plumbing fittings that have had a sticky sealer that requires a lot of force to overcome. In normal plumbing, these same fittings wouldn’t have a sealer so I can only assume they used these sealers to prevent leaks due to over the road vibration.

You might want to give Kimbrough's RV in Alabama a call. As you're probably aware they took over the wet bay floor R&R years ago and I'm sure they're very familiar with the fresh tank drain.

[vettenuts]

Well it's fixed. Tiffin Service basically did what I thought they would. They cut off the old setup and the carefully unscrewed the threaded fitting from the tank. Then screwed in a new piece and glued PVC valve and piping like the original. He gooped it up pretty well with some type of gooey sealer so not sure if that will impact future removal, but hopefully this lasts as long as I own the coach. They also filled the water tank to verify it is leak free.


$167 out the door.

[69Stang]

Originally Posted by vettenuts

Well it's fixed. Tiffin Service basically did what I thought they would. They cut off the old setup and the carefully unscrewed the threaded fitting from the tank. Then screwed in a new piece and glued PVC valve and piping like the original. He gooped it up pretty well with some type of gooey sealer so not sure if that will impact future removal, but hopefully this lasts as long as I own the coach. They also filled the water tank to verify it is leak free.


$167 out the door.

Glad you got it fixed. I've been watching in the event it ever happens to me.

[vettenuts]

One thing that I was thinking about is whether dirt gets on the ball of the valve while driving. I know the forward side of the drain pipe was pretty well beat. I am going to see if I can find a chair leg rubber foot to fit over the pipe and keep dirt from entering while driving.