Kitchen sink not draining

[tireman9]

2016 22QB Class-C Coachmen coach. Have used it many times with no problems. Getting ready for 2021 season I re-built the 2 gate valves (Black and Grey water).

 

Now I am having problems with the sink not draining. I have the HepVO waterless trap as OE. Have pulled it out and confirmed it is not blocked.

With the grey tank dump valve open, I can pour a gal of water in the sink and it drains out. If I close the dump valve, I can fill the sink with water, and it does not drain.

As soon as I open the grey tank dump valve the sink drains.

There is only a single roof vent in this model MH.

Sounds like a blocked grey tank vent but have no idea how or where FR ran the vent pipe. I assume they connected black and grey tanks to a single vent stack.

The sink is not usable and we are leaving next week for a 3-1/2 week tour out west.  Ideas appreciated.

 

 

Have confirmed the shower also does not drain unless grey tank dump valve is open.  Bath sink drains just fine. I thnk it drains to the black tank.

 

Used hose in the roof vent and heard water hitting water but since the roof vent is directly above the black tank I am guessing the grey vent used a T to vent it. Can't get to the vent pipe without removing bathroom from the RV.   Have contacted FR but am not holding my breath.  This situation makes using the RV almost impossible and I'm supposed to go to Gillette July 1

 

Edited June 24, 2021 by tireman9
add more info

[desertdeals69]

Hi Roger,  if you only have one vent through the roof there has to be a tee.  If you can't see the pipe inside the coach the only solution I know is to drop a inspection camera down the pipe and see where the tee is.  Once you find it use a snake and guide it into the tee going to the gray tank, then rotate the snake and push it in until it hits the bottom of the gray tank.  Good luck.  See you in Gillette, we are in Belvidere Il now and will leave here on the 30th to go to Gillette.

[tireman9]

I sent email to Service director at Coachmen asking about the venting of the grey tank. Right now it looks like I would need to remove the bathroom walls to find the T connection.

Not gonna happen. I would leave a day early and park in front of Forest River in IL first and demand they tell me how to fix their poor design.

[rayin]

I have an idea, good/bad I don't know. I wonder if reduced pressure compressed air into the kitchen sink with drain valve closed would dislodge any obstruction in the hidden vent pipe? Like hold a rag around the air nozzle for a few seconds at a time?

Attempt at your own risk, that idea comes when I'm very tired. Today I mowed 1.5 acres, trimmed, then removed and installed a new dishwasher in our house. Now if my heart DR. would just allow a shot of bourbon or  brandy I'd already be asleep  instead of getting crazy ideas.

[tom73]

Here is another suggestion....... Fill the sink, keep the grey valve closed and use a plunger if it will seal in the sink. The key is to try to work the plunger fairly fast and then push down hard to get it compressed. Then pull it back up quickly. That may dislodge what ever is lodged. With the grey tank empty the sink should drain some until the tank gets some water in it. You can also try the same thing in the shower.

[dickandlois]

Roger, I'm wondering if your gray water tank is equipped with one of these devices?

They work like a one way valve to keep the black water fums from entering the coach. Just a thought!

Link to some information.    https://hepvo.com/

Rich,

HepvO can be installed on a bidet and any other bathroom / kitchen application where a 1 ¼” or 1 ½” tubular p-trap is normally used.  Hep_vO is not suitable for use on toilets which have a 4” trap built in as part of the complete fixture.

Edited June 25, 2021 by dickandlois

[manholt]

Vapor lock is a common occurrence in a "rolling earthquake!"

Ray, Rich, your on to something! 

[kaypsmith]

14 hours ago, tireman9 said:

I have the HepVO waterless trap as OE. Have pulled it out and confirmed it is not blocked.

Just a thought, have you verified that the HepVO valve is not installed backwards?

When installed at any angle other than vertically, the HepvO must have ‘ribs down’ to ensure correct drainage.

HepvO valves must be installed in the correct direction of flow which is clearly marked on the body of the product.

Edited June 25, 2021 by kaypsmith

[tireman9]

3 minutes ago, kaypsmith said:

Just a thought, have you verified that the HepVO valve is not installed backwards?

Yes not backward. Has worked for 5 years then stopped working last week.  Only thing I did was rebuild the two gate valves.

[tireman9]

11 hours ago, tom73 said:

Here is another suggestion....... Fill the sink, keep the grey valve closed and use a plunger if it will seal in the sink. The key is to try to work the plunger fairly fast and then push down hard to get it compressed. Then pull it back up quickly. That may dislodge what ever is lodged. With the grey tank empty the sink should drain some until the tank gets some water in it. You can also try the same thing in the shower.

Problem with using a plunger when you have a Hepvo it turns the rubber valve inside out. Had to remove the Hepvo and get the valve back in proper position.   The fact that the shower also does not drain untill I open the grey dump valve points to there being no venting of the grey tank.

 

[wildebill308]

I think the inspection camera is a good idea. Could be several things. Could be plugged up by mud dober nest. Could be the vent has slipped down into the tank till it is on the bottom of the tank and won't vent.

Bill

[hermanmullins]

Kitchen sink--- shower, both will not drain unless gray water dump valve is opened. That leaves the bath sink. how does it drain? Bad or good? If it is also bad or no then it is very simple, Stopped Up Vent Pipe. Just for kicks go up on top and run a hose down and try to remove or wash out any stoppage. Then try the drains. 

😉You can always leave the gray tank open while driving and hope it is raining as to not draw any attention to your rig till you can get to your hook ups. I wont tell if you don't. 

Herman

[tireman9]

GREAT NEWS. IT"S FIXED.

 

Forest River returned my call!

After some conversation and discussion with a couple people at FR they asked how level was the coach.

I said nose low 4" to 6" as that was where I park it in front of my shop when servicing the coach.

They said to move it to level spot. I did and the sink immediately drained!!!!!!  Am calling them back to thank them for

the observation and suggestion.

[hermanmullins]

Who would have thunk that!

Amazing, that someone actually call you back. Glad you are able to drain your sinks now.

C U N Gillette.

Herman 

[tireman9]

The "Fix" makes sense now that I have more info.

The grey tank has direct connection to shower but there is a Hepvo "valve" horizontal and maybe the "nose down" of the RV prevents water to flow as that would put the exit not level which the HepVo wants.

I think the sink drains into a different horizontal line which when tilted must block the flow into the tank and air flow out of the grey tank to the black tank vertical vent as it connects with a T fitting.

 

Bit complex but as soon as I got close to level the sink and shower both drained quickly. So it looks like I will get to Gillette after all.

 

 

Ain't RV life fun?

[rayin]

HURAAY! All is  well, enjoy your trip to Gillette. Watch the hot weather.

 

[kaypsmith]

Strange thing about liquid, it doesn't flow uphill without a pump, LOL.😀

[wildebill308]

Glad you got that problem solved. I was about out of sensible suggestions. I was about ready to say take it to Camping World! See I was out of sensible suggestions.

Bill