Black Tank Flush Stopped Working

[davegood]

I have a 2011 Sunseeker 2300. I have used the black tank flush many times without a problem. Suddenly it doesn't work.
Does the safety valve just go bad, or does solid waste block the nozzle(s)?

What is the connection to the black tank? Single or multiple openings? How far up the tank? I'm afraid to put too much pressure into the flush. I'd hate to pop a tube and leave the black tank with a hole somewhere.

[Hoglou]

I dont know if there is a check valve or not in the line, but I would not be afraid to run regular hose pressure to the line. The pex lines and fittings will take normal house pressure that is prob under 60 psi.

Sounds like the jet tip is, well, gunked up. I would try a little pure CLR pushed with some compressed air at 60 psi, leave the air line for an hour. If NO JOY maybe pull the air line and let the CLR sit may over night.

If NO JOY I would then try a tab bit of (eco) drain cleaner safe for plastics, pushed by a water hose, but this could be touchy if the drain cleaner gets on the gel coat exterior. Keep a second water hose ready for a rinse down.

Once it works again I would flush the lines and tanks.

[nomad297]

Your check valve/vacuum breaker has gone bad. Locate it and replace it. I seriously doubt the outlet is clogged. That would be close to impossible.

Bruce

[bubbles]

Originally Posted by nomad297

Your check valve/vacuum breaker has gone bad. Locate it and replace it. I seriously doubt the outlet is clogged. That would be close to impossible.

Bruce

May be but that's what happened to mine. Disconnected output side of check valve/vacuum breaker and pressurized tank input tubing with air to unclog nozzle. I suspect TP had settled on nozzle and dried before I needed to dump. I think it happens a lot.

[Hoglou]

Where is the black flow check valve in the sunseeker for the black water flush? At the water line input like for park water? It seems reasonable to clear that step first...

[Witch Doctor]

Originally Posted by Hoglou

Where is the black flow check valve in the sunseeker for the black water flush? At the water line input like for park water? It seems reasonable to clear that step first...

Can't tell you were it is but it is required by law to be inline. Most are located in like your cabinet in the bathroom, but like mine is located behind the shower wall impossible to get to. I can see it when I remove my faucets but it's impossible to remove or replace. That's more then likely then your whole system blocked up at every jet.

[Hoglou]

I think I will pull the black water flush connection when the rain leaves and see if it is in the same place as the fresh water. If so an easy maintenance location.

Maybe davegood will do it sooner....

[bubbles]

Originally Posted by Hoglou

I think I will pull the black water flush connection when the rain leaves and see if it is in the same place as the fresh water. If so an easy maintenance location.

Maybe davegood will do it sooner....

Here is a view showing a typical install. Your check valve may not look like the one shown and the location could be anywhere but this may help with the search.

[fonzie]

This is typical installation of vacuum break valve.....

[davegood]

Thanks for all the help. I fear I have found my valve as per the diagram in the above message. It is behind the bathroom sink, at the very top, and also behind other water lines. I think it is impossible to get to.
Would banging the thing possibly get it to work? I'll try that today.

[nomad297]

Originally Posted by davegood

Would banging the thing possibly get it to work? I'll try that today.

Banging it might very well work, but you should try doing it first with no water pressure and then with water pressure. I am a plumber and I know that a swift whack with the jaws of a Channellock is the remedy to many problems.

Bruce

[Hoglou]

So on a sunseeker the water for the black flush enters from the outside of the coach, goes to a vacuum break somewhere in the coach and then back to the black tank?

Well you got me to walk out in the rain. The B&B manufactured inlet for the black water flush is identical to the external (park) water inlet product. I am still betting that the back flow check valve for the black water flush is just behind the three screws holding it to the exterior coach wall. Why would FR do more than required? That alone is whole new thread...

I am not a plumber so is the vacuum relief and back flow preventer the same thing?

or am I (punch line here) all wet.....

[Witch Doctor]

In simple terms YES. There is a valve in the black vacuum valve that can stick.

[Hoglou]

B&B inlet

[bubbles]

Originally Posted by Hoglou

So on a sunseeker the water for the black flush enters from the outside of the coach, goes to a vacuum break somewhere in the coach and then back to the black tank?

Well you got me to walk out in the rain. The B&B manufactured inlet for the black water flush is identical to the external (park) water inlet product. I am still betting that the back flow check valve for the black water flush is just behind the three screws holding it to the exterior coach wall. Why would FR do more than required? That alone is whole new thread...

I am not a plumber so is the vacuum relief and back flow preventer the same thing?

or am I (punch line here) all wet.....

Yes, the connection for the BT clean out looks identical but there is no check valve behind it. Only heard of one unit that had both the inside and outside check valves (I think it was a manufacturing mistake). There is not supposed to be 2 check valves in series for the BT clean out. See a previous post with image and read verbiage on that sheet. I have looked at other companies that make BT clean outs for rv manufacturers and they all say the same thing. The install is dictated by IAPMO TSC 27 if done by an rv manufacturer. A backflow preventer may not be vented to the atmosphere but a vacuum relief valve will be vented to the atmosphere. Our BT check valves are a combination of a spring loaded back flow preventer and a mechanical shut off plunger vented to the atmosphere which allows it to seal off the input side once the pressure is removed. The terms are all used interchangeably because the function is the same but in reality how that function is accomplished could be very different.

[CLewis]

If you have stinkbugs in your area - our previous Heartland twice had the check valve clogged by stinkbugs! When we went to get a new valve, another customer came in with a "broken" check valve. We tapped it on the counter and a stink bug fell out! Our check valve was behind the shower controls. As an aside, one year when I started the water heater, it started smoking - the entire gas line was filled with stink bugs and they caught on fire! We had installed all of the bug screens as an extra precaution on the vents but they can squeeze in anywhere.

PS - We are much much happier with our Forest River Rockwood Windjammer!

[Hoglou]

Great info about the valve.

Thanks!

[bend302]

CLR fixed my clog. Poured it into hose until hose was full and pushed it in with water.

Worked really quickly

Bill

[davegood]

" I am still betting that the back flow check valve for the black water flush is just behind the three screws holding it to the exterior coach wall. Why would FR do more than required? That alone is whole new thread..."

Wouldn't that be nice. However the flush (behind the three screws) connects to a verticle tube that runs up to the very back of the sink, connects to the backflow valve, then another tube runs down to the black tank. Other water lines were installed in front of the valve, making it inaccessible. A horrible design. Shame on Forest River!

[Hoglou]

I think I found my next mod...