External black tank flush fitting b/o

[David G]

G’day, I have a 2004 Forest River Wildcat 27RL 5th wheel TT. There is an external “San-T-Flush” fitting that is used to flush the black water tank when dumping. 
The last 2 trips out, I connected the hose to the fitting and the water would not flow. Normal water pressure but no flow. I don’t know where the problem lies; has anyone else had this problem? Does anyone have a possible solution? TIA

[TXiceman]

Three things to check.  Two should be under the bathroom sink area.  A check valve and an anti-siphon valve.  And last is the nozzle in the tank ... It can be plugged.  This require getting the under belly loose  and pulling the nozzle.  It is typically mounted to the tank with a sealant and 2 to 4 screws.

Ken

[Randyretired]

41 minutes ago, TXiceman said:

Three things to check.  Two should be under the bathroom sink area.  A check valve and an anti-siphon valve.  And last is the nozzle in the tank ... It can be plugged.  This require getting the under belly loose  and pulling the nozzle.  It is typically mounted to the tank with a sealant and 2 to 4 screws.

Ken

Our tank nozzle was plugged when we purchased the 5er used.  The only way to remove it was to remove the tank.  Simple problem, complex fix.

[Pat & Pete]

The flush hasn't worked in our rig in years .

I use one of these :

[Kirk W]

5 hours ago, David G said:

I don’t know where the problem lies; has anyone else had this problem?

That problem usually means that the flush nozzle is plugged up, which can easily happen either from sediment in the water supply or it can become coated to that point if the owner doesn't use it frequently. In looking at the installation instructions, it doesn't appear that you could remove the nozzle to clean it. I didn't watch it, but here is a video on it that comes from Winnebago which may help. 

[bobsallyh]

Had a friend that the flusher wouldn't pass water thru. Like TXiceman posted, we checked the check valve and anti-siphon device, both were good. Dropped some belly covering, took the flusher out, four screws and sealant held it in place. the small holes were blocked and he admitted that he didn't always use the flusher. We soaked it in Clorox, then drilled the holes a little bit bigger and replaced it. Worked fine from there on and his wife made sure he didn't take any short cuts. He was a fun guy, and I told him it was no wonder it clogged up because he was full of "it" and naturally his wife agreed.

[Wrknrvr]

  I will say that over a dozen years repairing rv’s.

 

  Do not flush your tank with water.

 

  Use one bowl of water for number 1;    Two bowls of water for number two.

 

  Use the system as normal . Figure out how long you can go before dumping. Have a clear fitting on the exit of pipe before you dump. When you see solids stop draining..

repeat for as long as you rv..

 

  Vern in a T-shirt 

[Ray,IN]

On 8/19/2020 at 8:56 PM, Wrknrvr said:

  I will say that over a dozen years repairing rv’s.

 

  Do not flush your tank with water.

 

  Use one bowl of water for number 1;    Two bowls of water for number two.

 

  Use the system as normal . Figure out how long you can go before dumping. Have a clear fitting on the exit of pipe before you dump. When you see solids stop draining..

repeat for as long as you rv..

 

  Vern in a T-shirt 

What other liquid do you recommend for flushing the black tank? I must have been doing it wrong the last 47 years.

[Wrknrvr]

   I have experienced a number of black tanks that were plugged through the years. After about four years of working on rv’s I started to ask how these customers were dealing with there black tank. Were they flushing  or not.

  So I really started to pay attention to how people did use there system.  Yep dam I must be nuts. everyone was testing me for how the hellll I thought flushing tanks was a bad idea. But I am the guy that had shi# up my armpit more than once from working on a plugged black tank.

 

  Yep had bad unrealistic discussions with friends over this thought. I finally started telling my friends that I would not work on a plugged tank if they flushed there black tank.

 

  So what found with a remote camera was that piles of (.     ) were sitting on the bottom of the tanks when there was no liquid in the tank.   Flushing a tank can leave a stiff pile sitting there. Then if one just happens to become an island.  It may just be moved around when it floats loose. Now buy chance will it float over to the down stream opening and pass the gate.    Butttt it may not.

 

  So for 10 years or so I have been dumping the black tank until I see solids start flowing. Then shut the waste valve fast.

 

  I have basically retired from rv repair so now I can share some of my experiences and tricks to repair things and solve problems for you.

 

  Now I am not a educated man.  But I have gone to School of Hard Nocks  in real life experiences.

 

   Vern in a dirty T-shirt. Just my thoughts.  But I could be wrong again

 

 

so I recommend to let the tank fill up 3/4 or so full . Then empty it till you see solids flowing out. Then shut the valve. I do recommend a clear fitting where the waste lines connects to the rv. So you can watch what is flowing out. Those solids can have time to dissolve in the tank for the next flush.

[David G]

Is it advisable to use an enzyme product like Rid-X I your black tank to break down solids?

[Kirk W]

5 minutes ago, David G said:

Is it advisable to use an enzyme product like Rid-X I your black tank to break down solids?

It won't harm anything and might do something helpful, but much more effective is to just be generous with your flush water and use no additives at all. 

When we first went fulltime I did use Rid-Ex faithfully for several years and then changed to just water. I was never able to detect any difference in the effluent. 

Edited August 26, 2020 by Kirk W

[David G]

Thanks for the input. This time out, we are using an ample amount of flush water as suggested; we will se what the effects are when we dump this time.
Historically, I have always flushed the black tank first and run it out of liquid and solids, as viewed through the clear elbow. Then I close the black valve and drain my 2 Grey tanks as I refill the black tank via the San T Flush valve. Finally, I re dump the black until she runs clear. I might even have to keep the San T Flush running to achieve that. Before I disconnect my sewer hose from the dump connect, I flush it with fresh water. This has worked well until the last 2 times out. 

[Randyretired]

We had a house boat that had black water tanks.  These tanks had top opening to suck the tanks out at the pump stations.  Gravity drains are not permitted there.  In any case  these top opening were large and you could see into the tanks.  If one didn't flush the tank out the small solids would dry before the next outing and would build up over time.  From this I believe it is important to flush the black tank before leaving it idle.  Keeping water in the tank may also be helpful but as water evaporates it leaves a ring.  More so with dirty water.  We flush out tanks at least periodically.   Especially before storage.

[David G]

Question for WRKNRVR;

Why do you recommend closing the drain when you see solids? Is there a reason why you would not want them out of the tank? Perhaps I am misunderstanding your comment. 

[Dutch_12078]

Since we always use an adequate amount of water when flushing solids into the tank, we've never had a problem draining them out of the tank. I have cleaned out some black tank "pyramids" for others over the years, although I've never needed to stick my arm in there. In most cases, the problem was caused by a misunderstanding about leaving the dump valve open on full hookup sites.

[Twotoes]

On 8/26/2020 at 11:21 AM, David G said:

Is it advisable to use an enzyme product like Rid-X I your black tank to break down solids?

Your RV black tank is not a septic tank it is a holding tank. If you dump regularly Rid-X is not in your tank long enough to do any good. Just use lots of water and black flush with fresh water every time you empty your black tank. Other additives can be used to help eliminate odor if desired. 

[David G]

Thank you for the responses. I do my best to thoroughly flush all my tanks whenever I take my rig out. I’ve never had a problem prior to the malfunction of the San-T-Flush system. I will continue to seek resolution for this clog problem. 

[Wrknrvr]

   My thinking is to not drain the tank completely so that you do not have a semi solid sitting in the valve itself when you close it.

 

  Yes I have had a few leaky valves that were caused by something getting stuck in the valve after it was rinsed.  With total long rinsing you by chance may wash something into the valve blade channel. And just by chance it may not seal properly after the fact. It might be more of a problem for tanks that are not used continually as a dry chunk mite just stop there at the valve blade seals.

 

  If you close the valve while things are flowing I think you have less of a chance getting something in your valve blade channel. If you notice it did not shut properly then pull it open and hope that subject flushes out as you still have some liquid in there.

  Use lots of water, and let the tank fill up fairly full. So time is on your side as nature will dissolve the solids and then flush out in a liquid form.

  It also could be worth thinking of putting some water in your black tank a few days before you use your rv after it sits unused for awhile. It may soften any solids up that were just sitting there.

 

  Just thinking,    Vern in a T-shirt 

 

[Wrknrvr]

 A customer had a gizmo like that years ago.

 

  Sewer drain on campground side plugged up. Solids plugged roof vent as customers were proudly doing something else.

  You guessed it ?.????    Black tank exploded.     ?hit everywhere in underbelly.  And I was stupid enough to clean there ?hit up. And install a new black tank.

 

   Never ever deal with someone else’s ?hit again.

 

  Vern in a ?hit shirt that day?