Water overflow in bathroom

I call it a bathroom but I mean the cupboard in which the toilet resides. On our last use I found that water was getting into the footwell. (shower was not in use at the time, only the basin). Our waste tank was getting pretty full at the time and I assumed that the water was just backing up through the waste drains in the tray. Is this the way it works on might we have a problem elsewhere?  Thanks, Barry

Yes - that's the way it works.
Soon after getting our first Nuevo I returned to the van to find the wife franticly bailing out water from the shower room floor into the kitchen sink (after washing the pots) - and panicking it was never ending!!!

Surely if you open the waste tap the water will then drain into the tank if it was full making it back up to the shower tray..

Keep a plug in the shower tray plug-hole!

SteveUK wrote:Keep a plug in the shower tray plug-hole!

Because we never used the shower (preferring site ones with more liberal hot water and no irritating clingy shower curtain) I sealed the plug in the drain hole, after it back-flowed from the waste tank. No subsequent overflow or smell.

Whale non return valves from CAK Tanks have solved it for me.

Hi Ron
Did you put a non return valve on each of the pipes between the waste tank and shower drains. Think there's 3 or 4 in total
Cheers

I wonder where the excess water goes when the shower plug is sealed in place !!!

[quote="steve00136"]Hi Ron
Did you put a non return valve on each of the pipes between the waste tank and shower drains. Think there's 3 or 4 in total
Cheers[/quote
[You must be registered and logged in to see this link.] .autosleeper-ownersforum.com/t8879-smelly-waste-tank-an-old-chestnut?highlight=waste
is a useful thread. As you can see from my posts I added one trap and 2 non return valves.
As you say, there are many pipes - in fact a total of 5 - 3 from the shower 2 of which join before reaching the tank, one from the basin and 1 from the kitchen sink at the other end of the tank.
When I first had our van we used to get waste water coming up into the shower tray if the tank was more thzn about 1/3rd full. I reckon it happened on left hand corners! I nagged Marquis and eventua, and ton the wayy put in some traps and valves. I rearranged their efforts so that it worked! I have non return valves (black) on each of the two pipes from the shower and a trap on the basin. There is nothing on the kitchen sink. Shower is perfect - good drainage and no backflow or smell. Basin has no smell but the trap has slowed emptying significsntly -I am tempted to remove the trap. Kitchen sink gets smells if we leave waste for a 3rd day but empties with a satisfying gurgle. Overall I am happy now.
Marquis gave me some pipes to sort out their efforts but all the bits are fairly cheap from CAK TANKS.
It is CRAZY that the waste outlet is about an inch above the bottom of the tank! It is impossible to empty completely.
Hope this long post and the previous post helps.

Thanks Ron - think that might be my next project.

We spent 3 nights on our son's drive , both before and after the 'van went in for the major surgery at A/S. A couple of days after arriving home, I went into the shower-room and noticed that the mat I'd put down on top of the shower mat was soaking wet.
I was completely mystified where the water had come from and I was fearing we had another problem.
However after reading the original post I realised that I'd not emptied the waste tank before we travelled home.
Yesterday I drained the tank and got almost four bucket-fulls out.
We'd never travelled with so much water in the waste tank, so hopefully the issue has now been solved.
Phew, that's a bit of a relief for this stressed-out mind.

Cheers, and all the best for problem-free travels for 2016.

Great!  Look carefully at pipe sizes on CAK catalogue.  If I remember correctly the non return valve fits easily into the tank spigot but you will need adapters or some rigid pipe to get the flexible pipe to fit onto the non return valve.  I had extra problems because Marquis' work had left the flexibles too short.
Sorry that there was a stray comma in my link - It should have been:-

[You must be registered and logged in to see this link.].autosleeper-ownersforum.com/t8879-smelly-waste-tank-an-old-chestnut?highlight=waste

You can see that I used some rigid pipe to join flexible to rigid and then to the valve or trap.  Nothing is glued - it is all push fit.  Once the flexible is on the rigid pipe it is th every devil to get off!

It's a good picture - the before is exactly like mine - I can see that you have swopped a longer flexible pipe with rigid to re use it in another position. Thanks

I was checking out the shower plumbing today and noticed that the shower plugs were simply sitting quite loosely over the drain hole. They have a rim along the edge which prevents them being pushed down to form a seal. After cutting off this rim with a pair of scissors and sanding them smooth they then formed a good tight seal.
Hopefully this may prevent any further flooding or at least reduce the risk - if not I will get the non return valves as advised by Ron.
Maybe worth a try!

Just read inspiredron post, I guess because I always empty the waste at every opportunity, I have never needed to add non return valves. I did experience slow emptying from the basin, as you say the waste pipe was looped low where it entered the tank. I just silkaflex 512 the pipe to the underside of the floor, jammed it up with a piece of wood overnight to set, it now flows as it should

Most of this waste water backing up problem is due to the waste tank air vents getting blocked. This usually happens when the tank gets repeatedly full and scum on the water surface gets into the vent holes. This dries and hardens when the tank is emptied.
On my similar age Nuevo, the tank vents are small holes drilled in each corner on the top of the tank. Run your fingers over the top of the tank and you can feel them. Now and again I crawl under and clear these holes with a bent wire coat hanger, never have the problem now.
Al.

Al,
I would strongly question your "most". My problem of waste coming up into the shower tray was first evident on our first trip with the brand new van!

I was really referring to the older models Ron, which is what the original poster has. Sorry for any confusion. Maybe the newer models don't have any vent holes. The way to find out I guess is to fill  up the waste tank with fresh water and see where it overflows from.
On mine when I first bought it, there was a small trickle from the top, it turned out only one of the four vent holes was clear. Now if I overfill, water cascades all round the tank rather than come up through the shower tray waste holes.
Al.

I find using a wheeled waste water container and open the tap on the waste tank then empty container regularly saves a lot of problems just my take on it., no smells, no water back up or blockages, easier to empty too.

That's a good idea if staying a while in one place on a recognised site Margaret, but like lots on this forum, most of my night time stops are either in the middle of nowhere in the UK or MH aires if on the continent, seldom staying in one place more than 2 nights.
 Using the onboard tank is essential in such circumstances.
Al.

I travel about,  most time spent on one site is 4 days, this was at the motorhome shows at Norfolk and Malvern, also the Weeting Steam Show, otherwise only 1 or 2 nights, everyone does what works best for them.

bikeralw wrote:I was really referring to the older models Ron, which is what the original poster has. Sorry for any confusion. Maybe the newer models don't have any vent holes. The way to find out I guess is to fill  up the waste tank with fresh water and see where it overflows from.
On mine when I first bought it, there was a small trickle from the top, it turned out only one of the four vent holes was clear. Now if I overfill, water cascades all round the tank rather than come up through the shower tray waste holes.
Al.

I suspect that on the newer models the input pipes may not be in the same place as yours. As you can see, on mine, the pipes enter the tank an inch or so below the top - the batroom ones are on the offside. So, as delivered without the valves, when I went round a left hand bend the waste water rushed to the offsid eof thetank and into the pipes and shower tray.  It would make more sense if the tank inlets were on top of the tank as they were on my Hymer.
You may also have the big screw bung on the bottom of your waste tank for drainage.  Mine is a flimsy pipe that is fitted to the side of the tank about an inch up - so the waste tank can never drain fully! 

Hi folks,We keep a bucket under our waste tank valve and we keep it open at all times,we empty it regularly ,we have no smells or back up waste as it goes straight out the van.We clean with milton before we empty for the winter. Hope this helps. Jubejube