Black Water Flush

[burghere66]

Following our trip I proceeded to dump our black and grey water tanks.  After dumping both tanks I connected the supply hose to the black water flush system.  The hose built up pressure but did not fill the black water tank.  I imagine the black water flush connection got clogged from the waste in the tank.  How does the flush system in the tank work?  And, any thoughts on how to unplug the flush system?

Gary B. 

2002 Monaco Windsor PBDD

[CMillet86]

I have this same issue so curious as to how to fix it also.

[vito.a]

There  are two possible issues.  Under the bathroom sink is an anti-backflow valve.  Sometimes they plug up.  Check here first as it's easier to access.  

On the other side of the tank is the flush sprayer and sometimes they plug up.  You have to remove the sprayer and use a small drill bit to unclog it.  

Picture of sprayer.   

Edited August 3, 2023 by vito.a

[Dr4Film]

Many members complain about this very problem. It is generally due to lack of use. If you are not back-flushing every time you dump the tanks then it will eventually clog up and not work.

You need to have access to the curbside of the tank bay. You may have to remove some sheet metal screws from underneath. Then remove the flush unit which will be either on the top or the side of the black tank. Drill out the holes a little then re-install using s good coating of silicone.

[burghere66]

Thank you Vito and Dr4Film for your rapid response!  I'll check it out tomorrow.  

Gary B.

[CLIFF918]

I had similar experience and changed both whirlybirds in the tanks. Since yours is a 2002 same as mine you should be able to access them from the propane access door and removing the inner cover. My black tank had a frozen up whirlybird so I replaced it and added one to the grey tank.

[Tom Cherry]

1 hour ago, burghere66 said:

Following our trip I proceeded to dump our black and grey water tanks.  After dumping both tanks I connected the supply hose to the black water flush system.  The hose built up pressure but did not fill the black water tank.  I imagine the black water flush connection got clogged from the waste in the tank.  How does the flush system in the tank work?  And, any thoughts on how to unplug the flush system?

Gary B. 

2002 Monaco Windsor PBDD

There are TWO possibilities

Clogged Nozzles due to Water SCALE...  Needs to come out.  Soak in CLR for a while.  Letter Drills (Small one) or Music wire is the tool to unclog them. 

MORE likely, but only based on my experience... Some type of trash and debris got inside.  You don't ordinarily flush a "Garden Hose" before you flush.  OPPS...sometimes BAD.  I have used a hose early in the season that was on the ground over the winter.  The bugs and insects and such LOVE that.  BINGO...NO PRESSURE... 

Here is my solution....after your remove it and clean out what is inside it.  I don't know if I have a whirly gig or just a nozzle...and mine is buried behind a solid plastic panel that will require major diassembly and possibly cutting the panel to removed....

Notice the picture above.  Notice the Washing Machine Washer in the fitting.  GREAT....PERFECT.

I have a fitting on the plastic panel...same type. It goes to a PEX and then to the actual fitting on the backwash head.  I have a short length (3 or 4 ft) of Garden hose with a male and female. I use a washing machine filter on the fitting on the plastic panel...like the picture. I then use Teflon Tape and screw on the short extension...temporary/but sealed.  Then I use a FULL FLOW (not the cheapie) 1/4 Turn shut off valve and it screws into the end of the Garden Hose extension.  I have a Pop In Cap to protect it when not in use. It is held on to the end of the Garden Hose Extension with a tether and zip tie.

I DO always FLUSH my hose at home.  I only use a hose in the MH that I keep coiled up and have the male and female TIGHTENED and Joined.  The good thing...I can turn ON the faucet...and then control WHEN I need backflushing by the 1/4 Turn.

If YOU have full or good pressure the LAST TIME...then some creepy crawly worked its way into the fitting (Dirt Dobber?) Or the hose you hooked up, the last time...had some debris in it.

You should be able to remove, hopefully clean or back flush or use compressed air. DO NOT BLOW IT OUT in the direction of the water FLOW...You will REGREAT it. 

That's my comment.  Good Luck.  Let us know what caused it and how you fixed it... 

[fredelkamp]

We made a video on this a while back on our solution. I don't think YouTube links are allowed so just search for "No Fuss Flush Not Working. Easy Black Tank Repair"

 

[burghere66]

As suggested by several respondents I gained access to the black water tank through the side panel just ahead of the rear passenger wheel.  I removed the spray nozzle from the side of the black water tank and and found it plugged and coated with hardened slime.  I used my drill with a small bit to clear  the holes.  After remounting it with silicone and the 3 mounting screws it now works great  once again.

Thanks to all that responded!

Gary

2002 Monaco Windsor PBDD