Answered Shower not draining properly

[Smk52]

We have a 2018 Jayco Greyhawk 29mv which is new to us and we are having a problem with the shower draining. Have done all of the usual things, drains not plugged, replaced air admittance valve, RV is level, grey water tank is not full. Water is very very slow to drain unless grey water dump valve is open. Called Jayco to ask where the grey water tank vent is and was told there isn't one. Any help will be greatly appreciated.

 

[Buly]

The tank should have air vent. The displaced air from the gray water entering the tank should be vented. Opening the dump valve relieves the air pressure and the shower drains properly.

 

[Smk52]

Then do you know if the Jayco 2018 has a grey water tank vent. Thank you for taking the time to respond.

 

[Buly]

I’m not familiar at all with your RV, but all tanks should have air vents. On my coach they are led all the way to the roof. They are plumbed to the high end (top) of the tank, and usually a hose is plumbed somewhere higher on the rv.
Vents work while filling or emptying the tank

 

[Smk52]

Thanks

 

[TheLooks]

Check the vent that is on the roof, it may be plugged and the problem is only apparent in the tub, for now.

 

[Smk52]

Thanks I will check that.

 

[Buly]

Mud dobers like to build their nests in hoses, pipes etc.

 

[RandyB]

Not sure of how your RV is built, but I think it's common to have a check valve in the drain line. It prevents backing up grey water from a full tank into the shower. Also known as a backflow preventer. If equipped, there is usually a warning sticker somewhere near the drain warning that tools and drain cleaners may damage the valve. Typically, the valve gets cluttered with hair, especially if there is a long hair user. The clog can be retrieved, but care must be taken to prevent damage. You just can't just jam stuff down the drain. Small, flexible mechanical finger grabbers are what can be used.

Think of the drain check valve as a thin, very flexible rubber duckbill inside the pipe. It allows flow easily in one direction, but when flow wants to reverse, the duckbill closes. Remove the grate from the shower floor. Start with only short penetrations to try and capture the clog. on mine, the check valve was about 10 to 12" downstream from the grate.

Warning, once you get the big wad and start extracting it, it's nasty. You'll need a strong stomach.

 

[AbdRahim]

I also occasionally pour some Dawn down all the drains to try to dissolve any grease which can hold hair etc. Dawn is even great for unclogging the toilet in the S&B.

 

[Smk52]

To follow up, I determined (despite what the Jayco tech told me) that the grey water does in fact have a vent that ties into the black water vent that goes to the roof. Applied low pressure air (30 PSI) to the water connection that is used to flush the black tank. Air bubbled up through the shower drain. Went to the roof and connected a plastic bag around the roof vent and had zero inflation of the bag. To me it was obvious that the vent was totally plugged. I expected to see one of those mud nest when I removed the cap but instead I discovered the quality people at Jayco had the pipe sticking up so high that the cap completely sealed it off. Removed about 3/8 inches of pipe and problem solved. Which tells me there has never been an active vent from day one. It might have worked if the cut on the pipe had been a little crooked but the cap made a perfect seal.

 

[AbdRahim]

Glad you found the answer. It seems to take two to three years to get all of the bugs worked out on these things. It can be frustrating at times.

 

[Buly]

Glad you solved the problem.
But you are lucky did not blow up a tank or a connector somewhere by applying 30 psi air pressure to the system. 30 psi maybe ok for your car tires, but for the plastic tanks could be disastrous.