Black tank flush sprays water onto electronics

[dg0603]

Hi all,

2022 Tellaro 20L. Black tank flush sprays water (clean hose water) all down behind the opposite wall bathroom storage cabinets. You can see it if you pull a drawer out and shine a flashlight behind.

I can still stick a hose in the toilet for the same effect so it's not an emergency.

Taking it into the dealer soon anyway for a warranty list.

Thor strikes again!

[wrapped]

Your check valve is either stuck, backwards or broken, it's a cheap, usually easy fix. Find and follow the waterline from black tank flush it should go up to a black plastic check valve and come out the other side of valve. When you find it have someone turn on water see if it's leaking from connection or out of top of valve. The valve is a $15. fix.

[16ACE27]

Originally Posted by wrapped

Your check valve is either stuck, backwards or broken, it's a cheap, usually easy fix. Find and follow the waterline from black tank flush it should go up to a black plastic check valve and come out the other side of valve. When you find it have someone turn on water see if it's leaking from connection or out of top of valve. The valve is a $15. fix.

Check valves don't leak outside the system. It's a vacuum breaker.

[wrapped]

Excuse me, "Newmar RV Vacuum Breaker Check Valve "
RecPro RV Vacuum Breaker Check Valve
And so on.

[dg0603]

Thank you for the input. It look like a very difficult place to get to. Do I have to pull out any large portion of the bathroom?

[JSkate]

Look behind your shower valve bezel for the check valve/vacuum breaker.

[Pete'sMH]

These vacuum breakers notoriously are unreliable. When mine failed and made a big wet mess I decided to just bypass the thing. I added a one way check valve (there’s already one but I added a second). It’s not code, but there is zero risk of contaminating the fresh water system as I use it so I’m happy with my simplified system.

[dg0603]

If the problem is with something behind the wall with the faucet (vacuum valve), why is the water spraying in a pattern that seems to be across the ceiling and down the wall opposite from the faucet behind the cabinets?

It almost seems like there is something disconnected or leaking up in the ceiling above the bathroom.

And I'm not saying I know anything, could be wrong.

I'd love to fix this myself, and probably could....but I'm daunted by the prospect of having to pull out any of the bathroom structure to do it.

And thank you for all the answers I've gotten.

[16ACE27]

Originally Posted by dg0603

Hi all,

2022 Tellaro 20L. Black tank flush sprays water (clean hose water) all down behind the opposite wall bathroom storage cabinets. You can see it if you pull a drawer out and shine a flashlight behind.

I can still stick a hose in the toilet for the same effect so it's not an emergency.

Taking it into the dealer soon anyway for a warranty list.

Thor strikes again!

Originally Posted by dg0603

If the problem is with something behind the wall with the faucet (vacuum valve), why is the water spraying in a pattern that seems to be across the ceiling and down the wall opposite from the faucet behind the cabinets?

It almost seems like there is something disconnected or leaking up in the ceiling above the bathroom.

And I'm not saying I know anything, could be wrong.

I'd love to fix this myself, and probably could....but I'm daunted by the prospect of having to pull out any of the bathroom structure to do it.

And thank you for all the answers I've gotten.

Faucet? Ceiling? Words not used before. This may be more screwed up than a backwards vacuum breaker.

[JimOIB]

Did this just start or has it been an ongoing problem? Like everyone else I think it is the vacuum breaker - just not sure how it failed. Could be a few things:

1) The vacuum breaker itself has failed internally
2) One of the connections to it has failed
3) if long term issue then it may be installed incorrectly - water connections reversed or the orientation is wrong for gravity to help close it.

As far as water on one side of the coach - water does seek the least path of resistance for flow - if your cabinet side is lower than the breaker side water will go that way. Or…you breaker is on the toilet side of the wet bath and not the shower head side.

Download the schematics from the Thor Owners site and you will have a better idea where to look.

[dg0603]

Been that way since delivery. Just discovered it a couple months into ownership. First warranty visit is scheduled.

It think it is something in the ceiling. A loose fitting or disconnection. We'll see.

[MLP]

Originally Posted by dg0603

Been that way since delivery. Just discovered it a couple months into ownership. First warranty visit is scheduled.

It think it is something in the ceiling. A loose fitting or disconnection. We'll see.

There are no water lines in an RV ceiling. There maybe a bad leaking PEX crimp or it is the brass RV vacuum breaker. Replace the plastic one with a good quality Watts brass RV vacuum breaker. If necessary, get PEX adapters to install it. Never found a complaint about the brass switch out. The vacuum breaker provides an air gap between your black tank and your fresh water line when there is not any pressure to it. Check valves do not, and are not approved for fresh to black water attachments. Check valves can allow a leak back into an unpressurized system. That is why thy are not for this type connection. The vacuum breaker is ether behind a bathroom sink wall or shower wall. They must be installed well above the toilet level. Most of the time they are well above the minimum height from the RV manufacture. Use a mirror and a flash light to see it.

[larrysfixit]

Originally Posted by 16ACE27

Faucet? Ceiling? Words not used before. This may be more screwed up than a backwards vacuum breaker.

Ted if it were on my 2018 ACE 29.4 (which is similar to yours) the shower wall would have to come out. it shows the pluming drawings show it at a level above the fresh water fill. And I looked and the blue lines run up there. On something as small and compact as a 2022 Tellaro 20L I can believe it is up there on the wall on the drivers side behind the wall of the bathroom. depending where the water input for the flush is of course.

[Connie Ahlman]

We had trouble with water running across the floor inside our new 2019 Vegas the first time we tried to flush the black tank. When we got home from our first trip when this happened the dealer checked it and the connection into the tank that the supply line was fastened to was broken. They had to replace the tank, as the connector was molded into the tank and they didn’t think a “fix” would work.

[push toy]

the black tank flush on my vegas 25.6 wouldnt work. I bought a new flush kit and just ran a new one. not very hard just a lot of cralling around under the coach. Quicky flush at amazon. hooked it up to the same connection that the factory put in works and looks factory.

[RonRM]

I would get a snake-cam (endoscope), $20 on Amazon...start looking behind the walls to see where the water is coming from.