Leaking black tank flush under sink

[T L Johnson]

Hi friends! Needing more help.

Please see photos

On this new 2020 rockwood geopro 19fbs, the black tank flush line is routed under the bathroom sink cabinet, into a connector inside cabinet, at the top, then back down into the tank.

Its leaking. On my first use of the flush I went inside and a bunch of water was on bathroom floor, so I traced it under the cabinet.

Why wouldn't the line just go into blank tank, instead of cabinet and the connector? I thought maybe there was a valve there to turn, but I dont see it feel one.

Obviously the connectors aren't tight, so its leaking badly.

About 85 days and , 5 trips and 1500 .miles into this unit.

Will be back to selling rv dealer shortly.

Any insight on this tank flush routing design is appreciated, thanks!

[Mr. Dan]

Originally Posted by T L Johnson

Hi friends! Needing more help.

Please see photos

On this new 2020 rockwood geopro 19fbs, the black tank flush line is routed under the bathroom sink cabinet, into a connector inside cabinet, at the top, then back down into the tank.

Its leaking. On my first use of the flush I went inside and a bunch of water was on bathroom floor, so I traced it under the cabinet.

Why wouldn't the line just go into blank tank, instead of cabinet and the connector? I thought maybe there was a valve there to turn, but I dont see it feel one.

Obviously the connectors aren't tight, so its leaking badly.

About 85 days and , 5 trips and 1500 .miles into this unit.

Will be back to selling rv dealer shortly.

Any insight on this tank flush routing design is appreciated, thanks!

Yes... lots of topics here about the black tank flush vacuum breaker/check valve being required by code to be higher than the top rim of your toilet. I wish mine were in the sink cabinet instead of in the wall behind my shower surround - although mine hasn’t leaked in 6+ years.

[T L Johnson]

Originally Posted by Mr. Dan

Yes... lots of topics here about the black tank flush vacuum breaker/check valve being required by code to be higher than the top rim of your toilet. I wish mine were in the sink cabinet instead of in the wall behind my shower surround - although mine hasn’t leaked in 6+ years.

Thank you. Wow, behind wall is not a good design!

[itat]

Don't bother getting the dealer to fix it. You have 2 options. Replace it with a good quality brass vacuum breaker valve in the same location (this is what I did) or replace it with a 90 deg bend and use a hose bib check valve on the supply hose. Here’s a picture of my replacement using a Watts LF288A anti-siphon vacuum breaker valve and 2 brass male-to-male nipples.



Here is a link to a hose bib check valve.

https://www.homedepot.com/p/Everbilt...Z4EB/205815672

[T L Johnson]

Originally Posted by itat

Don't bother getting the dealer to fix it. You have 2 options. Replace it with a good quality brass vacuum breaker valve in the same location (this is what I did) or replace it with a 90 deg bend and use a hose bib check valve on the supply hose. Here’s a picture of my replacement using a Watts LF288A anti-siphon vacuum breaker valve and 2 brass male-to-male nipples.

Attachment 237476

Here is a link to a hose bib check valve.

https://www.homedepot.com/p/Everbilt...Z4EB/205815672

This makes sense.

Funny....after morr reading here, and 90 days into the trailer, I hadn't expected to be having to get so involved in my own repairs so quickly.

Am guessing now that RVing means learning plumbing and electrical skills.

Already gained a lot of hitch and weight skills.

Onward!

[babock]

Or just do what I did and replace with a brass 90° fitting.
https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

[itat]

Mine started leaking on the 2nd or 3rd trip. It definitely helps to be handy. These things are not maintenance-free no matter what brand RV you buy.

[itat]

Originally Posted by babock

Or just do what I did and replace with a brass 90° fitting.
https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

The previous owner of my last TT did that, too, except he used a plastic fitting. As I stated in my previous post, the hose bib check valve is required if you replace the factory valve with the 90 degree fitting. It’s inexpensive at under $8 so no reason not to use it. I did.

[T L Johnson]

Originally Posted by itat

Mine started leaking on the 2nd or 3rd trip. It definitely helps to be handy. These things are not maintenance-free no matter what brand RV you buy.

Thank you

[T L Johnson]

Originally Posted by itat

The previous owner of my last TT did that, too, except he used a plastic fitting. As I stated in my previous post, the hose bib check valve is required if you replace the factory valve with the 90 degree fitting. It’s inexpensive at under $8 so no reason not to use it. I did.

Thank you

[chriscowles]

Originally Posted by T L Johnson

... Am guessing now that RVing means learning plumbing and electrical skills. ...

And a little bit of carpentry and general handyman skills.

[lesptr]

Originally Posted by babock

Or just do what I did and replace with a brass 90° fitting.
https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

I’ve replaced mine twice. I will be doing the 90 degree fitting if there is a 3rd.

[lesptr]

Originally Posted by itat

The previous owner of my last TT did that, too, except he used a plastic fitting. As I stated in my previous post, the hose bib check valve is required if you replace the factory valve with the 90 degree fitting. It’s inexpensive at under $8 so no reason not to use it. I did.

Why is it required?

[chriscowles]

Originally Posted by lesptr

Why is it required?

To prevent the potential for siphoning from the contaminated black tank sprayer back into a potable water system. It's the same reason outside hose bibs have anti-siphon attachments.

[babock]

Originally Posted by chriscowles

To prevent the potential for siphoning from the contaminated black tank sprayer back into a potable water system. It's the same reason outside hose bibs have anti-siphon attachments.

In the event the system you were using lost water pressure, while you were flushing, , then a vacuum occurred and you were flushing while your black tank was full.

A vacuum break is required on a dishwasher too. I plumbed mine straight to the disposal.

[The Evil Twin]

Abandon that interior one in place and splice an in-line one under the TT. First mod I did. After reading about all the folks that had water shooting out of their bathroom, I wanted to nip this off before it happened.