white hose under bathroom sink

[rafael33155]

there's a white hose underneath the the bathroom sink it's not the cold or hot water it goes up then loop down and it got sort of a black connection where it loops under the sink and when i turn the water on it start to drip does anyone know what that hose is for and what is the connection at the loop for?

[Irlpguy]

On some units that is where the Black tank anti siphon valve is located, mine included. It should have no water going to it when you are not flushing the black tank.
Whatever it is there must be a poor clamp holding the hose to the "black thing" or it may indeed be cracked or broken. You might be able to lower it to better inspect what the problem is.

[rafael33155]

thanks i'll check it out

[DQDick]

You are describing what in our rig is the backflow preventer on the black tank flush. We removed it and use an exterior backflow preventer. Even though you're not putting water thru there currently, if you have in the recent past the water caught in the downhill portion could still provide a drip for a period of time.

[oldelmer1]

Mine started leaking and when I pulled it out, it had a stink bug in it.

[PackerFan]

Hey Dick,

When you removed the back flow preventer what did you replace it with? Did it flow any better afterwards?

Scott

[steelpony5555]

Went to Lowe's and got the connections to eliminate the backflow preventer altogether and made it a straight shot. Most RV's don't even have one and don't see any realistic way that anything will come up and out of your blacktank thru that line anyways. But alas, it still don't work lol lol

[Phil P]

Hi

Does it look like this?

This is what the factory installed in place of a suction breaker on our trailer.







Phil P

[DQDick]

quote:Originally posted by PackerFan

Hey Dick,

When you removed the back flow preventer what did you replace it with? Did it flow any better afterwards?

Scott

I just bought an outside back flow preventer like restaurants use on hose connections and use it on the end of the hose attached to the outside back flush connection.

[jcurtis934]

The "back-flow" preventer is under the bath sink a lot of times and this is used for the black tank rinse water supply line that goes to the black tank. Sometimes, they aren't tightened from the factory (mine included), sometimes they are bad on buying your unit. They always emit a slight spray of water out of the relief port when the tank rinse water is first turned on. Always! For this reason, I took mine out and replaced it with the right metal connectors on a short lenght of pex tubing as I have the pex crimping tool to crimp the copper bands used with metal parts. If you use the plastic connectors, then you need to use what are called oedeaker clamps, which are a metal ring that has an area on its side where a special set of crimpers are used to tighten the ring. These look like old fashioned nail pullers with a rounded front face BUT the mating surfaces are very dull and rounded so not to harm the crimp ring. Home Depot sells the copper ring tool, but ACE Hardware and Lowes sell the other crimper tool that is used for the oedecker clamps. Oedecker clamps are what is used in the brewing industry for clamping the gas and service lines on beer delivery lines. Hope this knowledge helps folks. John

[NCFischers]

When mine quit working, I went to my local RV repair place looking for a replacement. They told me that Keystone is the only one that uses them. I removed the preventer and the associated plumbing and now I have a direct line from the convenience center to the tank.

[WeBeFulltime]

When mine stops working or starts leaking it's coming off and going in trash.

[wjwheeler]

I had the waster "leak" behind the shower and running down the steps yesterday when I connected the hose to the tank flusher. If I understand all of the posts about this issue, I can simply cut the two pex pipes that are going up behind the shower and connect them together with no issues.

[mach111]

quote:Originally posted by wjwheeler

I had the waster "leak" behind the shower and running down the steps yesterday when I connected the hose to the tank flusher. If I understand all of the posts about this issue, I can simply cut the two pex pipes that are going up behind the shower and connect them together with no issues.

Yes, I did the exact same thing on our unit. No leak since.

[wjwheeler]

I had the waster "leak" behind the shower and running down the steps yesterday when I connected the hose to the tank flusher. If I understand all of the posts about this issue, I can simply cut the two pex pipes that are going up behind the shower and connect them together with no issues.