Blank Tank Flush

[HighFive]

I'm new to RVing and picking up a GD 303RLS next week. I have been reading and searching this site for a couple of years and have learned a lot. I was at the dealer today and had lot's of questions. One thing were were talking about was water hoses for city water and for the black tank flush. I have seen on here where 2 different hose are recommended to prevent contamination of the city water hose. The dealer said this was not necessary as the black tank connection had a built in backflow preventer and I could just move the city water hose to the black tank flush. Is this correct. If not do I use 2 hoses with a Y connector with shutoffs at the campground spigot. What's the best way to set this up? Thanks!

[Country Campers]

I'm new to RVing and picking up a GD 303RLS next week. I have been reading and searching this site for a couple of years and have learned a lot. I was at the dealer today and had lot's of questions. One thing were were talking about was water hoses for city water and for the black tank flush. I have seen on here where 2 different hose are recommended to prevent contamination of the city water hose. The dealer said this was not necessary as the black tank connection had a built in backflow preventer and I could just move the city water hose to the black tank flush. Is this correct. If not do I use 2 hoses with a Y connector with shutoffs at the campground spigot. What's the best way to set this up? Thanks!

Reading and searching on here for a couple of years, that's terrible (just kidding).
Welcome to the group.
This is another debated topic on here. The common opinion , I think , is to use 2 separate hoses from the water hydrant at the post. This leaves a less likely scenario for contamination. There is a back flow preventer , also known as a vacuum breaker , behind the water valves in the shower. This allows air back into the pipes when your shut off the flushing. This is higher than the tank and the inlet where you hook up your hose. Some here , or many , fear contamination from using the same hose for this as the same one you use for your drinking water. I have used the same hose on my previous TT for 10 years and still do on our new 5er and have not had any issues. This will be one of those , what ever you choose is right for you" questions.

Brian

[GeoffnCheri]

Reading and searching on here for a couple of years, that's terrible (just kidding).
Welcome to the group.
This is another debated topic on here. The common opinion , I think , is to use 2 separate hoses from the water hydrant at the post. This leaves a less likely scenario for contamination. There is a back flow preventer , also known as a vacuum breaker , behind the water valves in the shower. This allows air back into the pipes when your shut off the flushing. This is higher than the tank and the inlet where you hook up your hose. Some here , or many , fear contamination from using the same hose for this as the same one you use for your drinking water. I have used the same hose on my previous TT for 10 years and still do on our new 5er and have not had any issues. This will be one of those , what ever you choose is right for you" questions.

Brian

^^^ This^^^ Much like the Ford, Chevy, Dodge debate.

I am a member of the two separate hoses club. I have a blue hose for fresh and an orange hose for black tank duties. I use the orange hose for flushing of the black tank and rinsing of any additional sewer hose components as well. Fresh water components like filters and fresh water hose are stored in one container and black water hose and components, couplers, hose support etc stay in a another container. It is purely subjective for me but gives me piece of mind. I also usually use some sanitizer on the water source hook up.

Relax and welcome to the 303 family.

There is a very accurate saying in the backpacking world which is "Hike your own hike" I like to transfer this to our travels. What may work for some, may not work for others. Enjoy your 303 for your enjoyment.

[Lizardqing]

I am another of the two hoses club. Have a blue one that’s nothing but fresh drinking water and a black one for flushing the tank, washing the truck and camper, and when necessary the kids. There might be a check valve behind the flush connection, but mine still has water running back out of it after I disconnect it. So I added a ball valve connection on its hook up.

[Cate&Rob]

@HighFive . . . I would agree with your dealer. There is no way for black tank contents to contaminate the flush hose connection because of the vacuum break.

A hose should never be connected to the black tank flush unless it is pressurized and actively flushing the tank.
The real risk is those who connect one hose to their potable water supply and another hose to their black tank flush and then Tee these together at the faucet. Turn off the faucet (or lose park water pressure) and you have created a direct connection between your black tank and your water supply. Once again, the vacuum break is the only thing that prevents cross contamination.

The "two hoses connected at the same time" is a very common misunderstanding by many RVers at any RV park . . . and puts everyone in the park at risk if park water pressure fails and any one vacuum break fails on a full black tank.

Rob

[Cate&Rob]

There might be a check valve behind the flush connection, but mine still has water running back out of it after I disconnect it. So I added a ball valve connection on its hook up.

Lizardqing - The water running back out of the black tank flush when you disconnect the hose is the vacuum break doing it’s thing correctly. Adding the ball valve has prevented the vacuum break from working correctly as designed.

Rob

[Lizardqing]

Lizardqing - The water running back out of the black tank flush when you disconnect the hose is the vacuum break doing it’s thing correctly. Adding the ball valve has prevented the vacuum break from working correctly as designed.

Rob

Ok. Good thing I always open it back up then after I take the hose off. It’s mainly on there so I can stand to the side and not get covered, mine seems to be able to get that first bit out the door.

[HighFive]

Thanks for the reply's. It looks like the opinions are split. I think I will go the 1 hose option for now.

[JColeman]

With no offense to anyone and great deference to others who have done this longer...

Why would anyone not spend an extra few bucks for a separate black water hose just for the peace of mind? Worse comes to worst, it's a backup for your primary.

[camper1013]

I have a second hose for the flush. I'm not so much worried about the black tank backing up as the contamination from the dump station area. When your at the dump station watch what others do with the hose once. You'll never want your fresh hose anywhere near it. Not to mention if you accidentally drop the end of the hose in the danger zone around there.