Black Tank Flush System

[maximo]

I have a 2011 Big Sky 3580RL. It has the "Black Tank Flush" in it. After I drain the black tank I hook a hose to the flush fitting and turn on the water leaving the tank drain valve open. After a few seconds the water starts draining out the sewer line, I have a clear elbo on the line. I have read about problems with this system and would like to know what happens if the system is not operating right. If a problem does any water come out the drain line? Does some thing start leaking inside? If a leak inside where does the water go and can you see it leakin before it floods everthing? So far the system seems to be doing what it is designed to do.

Thanks,
Frank

[Tom S.]

Frank, the most typical problem I've read about (and experienced) is the check valve that is located between where the hose screws on, and the sprayer head. For whatever reason, the valve fails and little or no water can get through. On most units, it's a pain to get at to put in a replacement part.

[Art-n-Marge]

Tom pretty much describes the only problem that can occur and the unfortunate process to locate the check valve and replace it when things go wrong. In the meantime, I have one in my unit and it works great - no problems so far! I often close the black tank valve and leave the sprayer on for a while. As long as I can hear the water spraying in to the black tank I am very happy that I can use it to fill the black tank, then open the black tank valve to backfill and drain the tank repeatedly to get it clean! Do not leave this process unattended and there should be no problems. Then I stop the sprayer, close the black tank, drop some deodorizer down the toilet, fill the tank with 2 or 3 toilet bowls full of water (4-5 gallons), then it's clean and ready to store.

When this stops working I will not be happy about fixing this, but the MOC has warned me what to do, so I feel confident that my ire will be minimal and just another thing that might need a routine fix.

[tim43]

Or as happened in our case, you can flood the camper if the valve breaks and you are not monitoring what is going on.

[Irlpguy]

quote:Originally posted by tim43

Or as happened in our case, you can flood the camper if the valve breaks and you are not monitoring what is going on.

This is a common problem and we also had to deal with it early on. Fortunately for us ours was located under the bedroom sink and was reasonably easy to access and replace. The leak on ours showed up in the storage area where the hoses went up to the valve. Otherwise we have had no problems with the flush system.

[rdklein2]

Had the same problem as Irlpguy, with the exact same symptom. Location of defective part was as stated, Model 3150RL.

[oldelmer1]

My anti-siphon valve was located between the refrigerator and the shower wall on my 3150RL. It started leaking and the water ran down into the basement and down into the underbelly and out the front leg.

After I removed the anti-siphon valve, I found that a stink but had crawled up and got between the flapper and the O ring that allows the air in to anti-siphon.

So, I cut it out and reconnected the 2 pipes with 2 90* sharkbites.

[DQDick]

We removed the OEM valve and use an exterior one when we flush. We also start the flush as soon as we get a good flow coming out the sewer pipe. That way we get everything to flow out.

[HOOK]

We dont ever use the outside shower provided in the service closet, so I hooked the squiggly hose to the black tank flush, with an anti syphon valve ofcourse, and turn on the faucet as soon as black tank valve is open. Even use hot water on occassion. Works well for us.

[bncinwv]

quote:Originally posted by HOOK

We dont ever use the outside shower provided in the service closet, so I hooked the squiggly hose to the black tank flush, with an anti syphon valve ofcourse, and turn on the faucet as soon as black tank valve is open. Even use hot water on occassion. Works well for us.

Exactly what we do, other than when we are a beach. I then disconnect the blue line (the squiggly) from the black tank flush and put a garden hose sprayer on the end to use it for beach sand removal before tracking it all in the rig.
Bingo

[Recumbent]

We do what Larry and Bingo do by keeping a short hose hooked full-time to the outside shower connection, always turn on the hot and cold water fully and then open the knife valve to black tank and then sewer line knife valve. Use lots of water until see clear water flowing through clear elbow. Occasionally refill black tank and refresh being cautious not to leave water going into tank for more than 6 or 7 minutes (using smart phone timer) maybe 14 to 21 gallons depending on pressure.

[richfaa]

quote:Originally posted by Irlpguy

This is a common problem and we also had to deal with it early on. Fortunately for us ours was located under the bedroom sink and was reasonably easy to access and replace. The leak on ours showed up in the storage area where the hoses went up to the valve. Otherwise we have had no problems with the flush system.

I wondered where that valve was on our 13 3402. It was behind the shower wall on the 06 3400 and there was a access panel in the cupboard.

[Phil P]

Hi

My black tank flush system doesn’t have and never had any type of suction break valve or check valve installed at the factory.

Here is where the suction breaker was supposed to be under the vanity sink.



Here is where a check valve should have been.




When we replaced the convenience center and basement floor we installed a check at this water connection.



Phil P

[JandC]

X2 how DQDick and other do it. I found that by starting the flow at the same time I drop the black tank it gets a lot cleaner quicker.

[steelpony5555]

Don't be surprised if even after you replace that check valve it still don't work. I took out the valve and it is just a straight pipe now. I highly doubt any germs are gonna fight their way up and thru the hose to the water supply system so bye bye check valve. But my sprayer is still pretty weak and pretty much worthless lol lol..... oh well just doing it old school the way we did before the sprayers and using lots of water to flush it out...

[Phil P]

quote:Originally posted by steelpony5555

Don't be surprised if even after you replace that check valve it still don't work. I took out the valve and it is just a straight pipe now. I highly doubt any germs are gonna fight their way up and thru the hose to the water supply system so bye bye check valve. But my sprayer is still pretty weak and pretty much worthless lol lol..... oh well just doing it old school the way we did before the sprayers and using lots of water to flush it out...

Hi

The reason we put the check valve where it belongs was to stop the water from running out into the convenience center. Even with the suction breaker you get the water in the lines between the suction breaker and the convenience center gushing out of the fitting if there isn’t a check valve at the supply location.

Then couple that with the lack of any caulking between the fitting in the convenience center and you get water soaking into the wood.

Phil P