Community Forums

twojayhawks · 05-04-2018, 09:07 AM

I rarely use my black tank rinse but I know others use them regularly. I believe it is code to have prevention (or at lease wise) on hose bibb's at home. Plenty of CG's don't appear to use them. It seems like it would be awfully questionable if RV builders are not installing any backflow prevention with these black tank rinse features.

BFlinn181 · 05-04-2018, 09:26 AM

The RVIA (Recreation Vehicle Industry Association) that sets standards for RV builders, do address the flushers in their standards.

Typically black tank flush nozzles have vacuum breakers that prevent backflow. In tanks that have the valves factory installed, the vacuum breakers are sometimes found under a sink cabinet. If they fail, it becomes evident by their odor!

Dizzee2020 · 05-07-2018, 02:03 AM

I don't use black tank flush often but when I do use it I attach one of these valves to the hose bib prior to a short hose I dedicate to this task.

https://www.amazon.com/Valterra-A01-...backflow+valve

Double indemnity I guess but it gives me peace of mind that I'm not messing-up the campground's fresh water system. It always releases water when I turn off the hose bib pressure.

nothermark · 05-07-2018, 02:17 AM

The preventers they use around here look like a thread protector. Just an add on brass fitting. It took me a couple of years to find out that they were more than just a thread protector for the faucet.

FWIW I recall some folks talking about removing their built in protectors for various reasons so they are installed in the RVs.

wa8yxm · 05-07-2018, 09:57 AM

Short answer yes

I noticed when mine was new that when I disconnected from "The Flusher" I got a lot of fresh water backflow

Turns out there is a Vacuum breaker up above the tank where I could not see it, often it will be in the Bathroom. but mine is not.

Also some upgrades from "The Flusher" (that's an actual brand) have check valves as well Like the Tornado.

But there shoudl indeed be a vacuum breaker in most all installs .

STILL.. Practice good sanatary practice.

I use a Quick Disconnect. and along the paty is a "Y" with valves.. I make sure I have pressure to the "Y" before I open the valve to the dedicated FLUSH hose. That hose is only used to flush (Tanks and hoses) and never for fresh water.. And I disconnect from "The Flusher" when I'm not actively using it .

Mr_D · 05-07-2018, 10:01 AM

Around her all the hose bibs have them plus I add one on a "Y" shut off, then the flush valve also has one.

Forkyfork · 05-07-2018, 10:10 AM

This one is metal and holds up better than the plastic. You want to avoid using the screw to secure it unless you want it on there FOREVER.

Im switching out my wet bay faucet that has a vacuum breaker in it with a commercial faucet. Because there is no anti siphon I will be using one of these or a shower head one.

https://www.amazon.com/Mueller-108-9...ds=anti+siphon

Dutch Star Don · 05-07-2018, 11:50 AM

I've never checked closely, but I believe my tank sprayer has a backflow valve as part of the connection. I changed mine because I'm lazy and didn't want to pull out another hose to flush the tank, since I have a built in hose reel and cant use that hose.

I put a "Y" in the system where the water comes into the coach, before the water filter. I wanted to use non filtered water to flush my tank. No use wearing out a filter unnecessarily. I ran the plumbing up the side of the wet bay and across the top. I added a valve to the plumbing and then a short hose with a quick connect. When I use the flush, I connect the hose, open the valve and flush. When done, turn off and disconnect the hose.

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ghaynes754 · 05-07-2018, 01:26 PM

Bill, yes it will have a back flow preventer. Location depends on the coach. in a 4369 it is in the 1/2 bath under the sink. The current version is a small black device. They may have used the Camco style in the past. They do fail. Just replaced mine as I was getting a sewer smell in the half bath while driving. I had already replaced the AAV for the grey tank and replaced the tank sprayer. No more smell. The old one had failed. Easy to check by blowing into the output side. If it leaks then it is passing odiferous fumes if there is a vacuum inside the coach.

Adding one on the input hose side helps protect the park or your water tank but won't do a think if you have a bad interior valve for smell.

FatChance · 05-07-2018, 01:31 PM

I installed a brass backflow preventer between the vacuum breaker (brass replacement, under the sink) and the black tank. There is the original factory cheap backflow preventer behind the hose connection in the water bay. I also installed a brass back flow preventer at the hose connection. Water is going in, nothing is coming out.

Old-Biscuit · 05-07-2018, 01:38 PM

Quote:

Originally Posted by FatChance

I installed a brass backflow preventer between the vacuum breaker (brass replacement, under the sink) and the black tank. There is the original factory cheap backflow preventer behind the hose connection in the water bay. I also installed a brass back flow preventer at the hose connection. Water is going in, nothing is coming out.

That 'vacuum breaker' IS an:
Anti-siphon vacuum breaker backflow preventer device
Top is open to atmosphere (Anti-siphon vacuum breaker section) and has an internal check valve (backflow preventer)

Cheap style

Better style(s)

FatChance · 05-08-2018, 02:34 PM

Quote:

Originally Posted by Old-Biscuit

That 'vacuum breaker' IS an:
Anti-siphon vacuum breaker backflow preventer device
Top is open to atmosphere (Anti-siphon vacuum breaker section) and has an internal check valve (backflow preventer)

Yes, you are correct. I installed the brass backflow preventer between the tank and brass vacuum breaker in case the vacuum breaker malfunctioned, however unlikely. I like two different backflow prevention technologies as a backup. Belts and suspenders

jd956jd956 · 05-13-2018, 01:52 PM

Hi, Curious how often folks rinse their black tank...?

Dutch Star Don · 05-13-2018, 02:01 PM

When we're using the coach a lot, like during the summer, I don't rinse mine. Since I have two macerator toilets that use a lot of water, I don't have build up issues. Maybe twice a year, I do a thorough cleaning of the wet bay and flush the tank. I also drop in a bottle of grey tank cleaner about once a year. I try to do it when I'm running the dishwasher or the washing machine and tank advantage of the war water in the tank.

Since our black tank fills soooo fast and has to be dumped every 2.5 days on an average trip, I don't use chemical, unless the weather is warm and then I use Happy Camper chemical.