Black tank flush vacuum breaker.

[Beachcamper]

I have read some folks using a backflow preventer vs a check valve at the brass vacuum breaker. Their instructions also warn not to put any shutoffs downstream. Would a check valve be considered a shutoff? Sent an email to Watts to ask about using a check valve with their LF288A for RV use. Hopefully will hear back and post their reply.

The other option is going with the RecPro model which is made in the USA and has very good reviews. This would obviously be the simplest option for direct replacement. I just happen to have all the brass parts and the Watts on hand as it looks like a better built vacuum breaker. My concern is also the weight of the brass vs the plastic especially in the location it is in and all the added road bumps and vibrations it will be subjected to.

Also saw videos of just going without this piece and using a brass or plastic elbow and attaching a back flow preventer at water source. Lots of pros and cons of using this solution but it would eliminate any water leaks.

[TedS]

Beachcamper I don't think in this application the check valve would be considered a shutoff since it allows flow in the proper direction and does not block the vacuum breaker forward flow.

[Cate&Rob]

The "dilemma" on the Reflection 303 RLS is that to comply with the RVIA requirement of having the vacuum break above the rim of the toilet means putting it in a barely accessible location behind the shower wall and above the furnace where its "normal" potential to occasionally drip will get water on to the furnace and its less-than-waterproof control board . I have previously voiced my thoughts on the relevance of being above the rim of an RV toilet with a sealed flush valve.

Thus . . . if one were to decide to ignore the RVIA requirement of being above the toilet rim, the vacuum break and check valve could be in the plumbing basement where it is easily accessible and an occasional drip leak is not a big deal. The vacuum break would still be well above the black tank and can be slightly above the hose attachment. Just sayin' .

Rob

[TedS]

The code describes only the minimum elevation above the flood rim and not a maximum. The vacuum break valve could be on the roof and satisfy the code.

In my Reflection, the vacuum break valve is under the bathroom sink.

[Jlawles2]

I guess technically anything that prevents reverse flow of the water should be acceptable. Thus a check valve would work, but the vacuum breaker is there because it eliminates the possibility of the valve failing and allowing black water to enter the line.

This just my take on the whole valve thing, it's not a code interpretation.

[Cate&Rob]

In my Reflection, the vacuum break valve is under the bathroom sink.

Under the bathroom sink would be an ideal spot for the vacuum break . . . unfortunately, this would be a complex hose/pipe routing in a 303RLS.

Rob

[howson]

JCR GD or Beachcamper -- could you (please) post links to the brass fittings you found on Amazon? (TIA!)

[JCR GD]

JCR GD or Beachcamper -- could you (please) post links to the brass fittings you found on Amazon? (TIA!)

Watts Water Technologies 1/2 LF288A Watts 288A Anti-Siphon Vacuum Breaker 1/2 In., Brass, Lead Free: Plumbing Equipment: Amazon.com: Tools & Home Improvement

Amazon.com: Camco 23303 1/2" Back-Flow Preventer - Lead Free : Automotive

(Mods - please fix link if they show personal info. Not sure how the copy and paste of links works. Thanks)

[Beachcamper]

JCR GD or Beachcamper -- could you (please) post links to the brass fittings you found on Amazon? (TIA!)

This is the brass vacuum breaker

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

the check valve and fitting

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1


I am still waiting for watts to verify that adding a check valve or back flow preventer for this application is advised or not. I have all these parts in my kit from 2019. Went ahead and ordered a Rec Pro vacuum breaker as direct replacement of the OEM. I have water alarms in all places a leak could occur so I am ok with holding off on any repair until I need to. Mine is not leaking and black tank flush works for now.

[Beachcamper]

Watts has responded to my question on using an added check valve with their vacuum breaker posted above. They responded that It was not necessary to add one. I sent them the Rec Pro vacuum breaker specs and picture I wanted to replace with their brass one. However if I wanted to use one I could.

I asked about sewer smells if not using a check valve. He said “I would not worry about this if I were you.”

[Cate&Rob]

(Mods - please fix link if they show personal info. Not sure how the copy and paste of links works. Thanks)

Hi Jim,

When you copy and paste an Amazon link, it strips out the personal info that you see and replaces this with the Amazon account info of the person opening the link.
Just FYI . . . I used to wonder about this too .

Rob

[Jlawles2]

Cate&Rob Jim and Rob, the only issues I have ever had with copying the links from the browser address bar are make certain you use amazon.com vs smile.amazon.com to get the link. I use smile.amazon.com when placing orders as this is linked to a charity of my choice that Amazon will donate to. Found this a few years back, cost me nothing (I have compared prices).