Sink water coming up in shower drain

[kaza]

We have a 2007 tandem expanda and have found when pulling plug for sink to drain the water is coming up in shower drain. (Unless hold finger over plug so it drains slowly). Both drains divert to one drainage Hose.

Any suggestions on what we can do to fix this eg one way value and if so on which drain hose, sink or shower it both.

 

[Coastrunner]

I think there's a slight blockage in your single drain hose. I think it would be in the last portion of the drain hose, past where the two have diverted into one hose. What I think is happening is that the water cannot drain fast enough out, and back fills back up to the shower (because it's lower than the sink drain) and then slowly drains out past what ever the blockage is after that.

1. My first attempt to clear it would be with the use of a plunger. This is easy to do if there's only 1 drain but may be different with two. I think if you can plug one of your drains (probably easier to plug the sink) and then allow water to run down the shower, using a plunger push and pull it over the shower drain. This may loosen the gunk causing the blockage and free up the pipes.

2. If this doesn't work, then I think you may have to crawl under the van, undo the clamp or T piece where the drains meet, take the drain hose off and flush it out with your gargen hose. The garden hose should fit inside your drain hose and even push the gunk out as its turned on.

I reckon you`d have it sorted with these options.

 

[Aussiecris]

G'Day
Our problem was the length of our hose, When the sullage point in the van park is to close to the van and the hose is coiled up under the van we get to much back pressure (Ours will even pop a sink plug up out of the shower) a shorter hose seemed to resolve our issue.

 

[Aussiecris]

Forgot to mention
Other van manufacturers install a HepVo Self Sealing Waste Valve in the shower line
It's a one way valve that fits in line (Google) about $35
I only know this because the van next to us on the long weekend had his apart and I couldn't help but sticky beak

 

[macca]

Drains in Jayco's leave a lot to be desired. It is a common problem. Brad renewed all his drains to overcome that problem, others have as well. The other problem is for any drain to work it needs air. In caravans for some reason they don't worry, they just hook it up with crap tubing and hope for the best.

So suggestion. Completely renew drains and fit valve as suggested in above post. A search on the site should show some examples. I did mine as I just hated how the sink didn't even drain. In the 1st photo at the top right I fitted an air valve to let air in to the drain. That makes a big difference but getting rid of the tubing also helps. Cant help with shower example as I don't have a shower but I would fit that valve as suggested previously if you can get it in.


Cheers Geoff

 

[Bushman]

A commom problem, but have never had it happen even if our sink was draining slowy due to poor run in sullage hose, keep sullage hose run short as possible dont coil it up, I cut mine into 3 lenghts and use joiner if required 1 long and 2 short lenghts..
and has mentioned fit a anti flow back valve in the shower waste pipe, i haven't fitted one and dont have a problem. though you can hear the water gurgling from shower waste at times

 

[Burnsy]

This used to happen to us also. Replaced drain pipes with 40mm pvc as Brad did and added non return valves. I then bought 40mm sullage hose from Caravans Plus, cut into 1m lengths and join as required. Only a single outlet now, no manifold and drains quick!

 

[Hubble80]

Another option is to fabricate a grey water tank and fit under the rear of the van. Have inlets for both shower and sink waste, a small breather on top and one large outlet. Hook up the sullage hose and it can drain as it needs to. My father in law has done this in his Discovery and says it works a treat. He was unhappy at how slowly the sink would drain and how it would bubble into shower.

He only wishes now he had fabricated a larger tank. He is also going to put a valve on the outlet to allow you capture waste when free camping as some places don't allow grey water on the ground.

I am designing my tank at the moment am I am going to upgrade the drainage piping to a larger size as well as the tank which should improve it lots of percent!!!

 

[macca]

Air into the drain is the key, as Hubble suggested a breather on top of the tank makes a difference. Quite simple a jayco drains the same as a full coke bottle turned upside down. Then try it with a hole in the bottom of the bottle and see how quick it drains. Shot gun principle.

 

[DRW]

silly question I know, why do caravans have such tiny little drains in the first place, I mean really you could swallow the sink plug and not even know it?

 

[Burnsy]

silly question I know, why do caravans have such tiny little drains in the first place, I mean really you could swallow the sink plug and not even know it?

That's a good question!

 

[17triton]

I`d say $$$$$$$$ @DRW

 

[Pace]

silly question I know, why do caravans have such tiny little drains in the first place, I mean really you could swallow the sink plug and not even know it?

I've tied ours to the flick mixer. Pace.

 

[Rose]

We have a 2007 tandem expanda and have found when pulling plug for sink to drain the water is coming up in shower drain. (Unless hold finger over plug so it drains slowly). Both drains divert to one drainage Hose.

Any suggestions on what we can do to fix this eg one way value and if so on which drain hose, sink or shower it both.

We fixed same problem easily by creating 2 separate outlets one for sink one for shower

 

[Brad]

For me, the one way valve stopped anything getting to the shower.
But I have also found when emptying a sink of dirty dish water to create a whirlpool effect in the sink helps.
I bet it has something to do with the breather effect @maccayak describes with the breather concept because when I make the whirlpool it allows the air into the drain.

 

[Bushman]

A commom problem, but have never had it happen even if our sink was draining slowy due to poor run in sullage hose, keep sullage hose run short as possible dont coil it up, I cut mine into 3 lenghts and use joiner if required 1 long and 2 short lenghts..
and has mentioned fit a anti flow back valve in the shower waste pipe, i haven't fitted one and dont have a problem. though you can hear the water gurgling from shower waste at times

I have also just replace the sink outlet with a straight one instead of the standard one with the elbow in it, getting the new flexi tubbing through the floor was a bit fiddley, filled the sink to the brim,pulled the plug woooosh gone in about 10 seconds seam to be a bit quicker than the old one and creates its own suction/whirloop effect bit like a bath/basin does.

 

[CJ1177]

I have also just replace the sink outlet with a straight one instead of the standard one with the elbow in it, getting the new flexi tubbing through the floor was a bit fiddley, filled the sink to the brim,pulled the plug woooosh gone in about 10 seconds seam to be a bit quicker than the old one and creates its own suction/whirloop effect bit like a bath/basin does.

What size is the sink outlet, I was thinking of doing the same but didn't know what size to get

 

[Bushman]

What size is the sink outlet, I was thinking of doing the same but didn't know what size to get

It's actually the same size as factory outlet, however it is a straight outlet the factory one has elbow which restricts follow

 

[Brad]

Very nice @Bushman.

 

[AndrewC]

I just bought a spare sink plug, same size outlet and you then have a spare plug ready for when they break. Finish shower, put the plug in, simple