Motorhome Facts Forum banner

waste tank filling far faster than the fresh water empties

3347 Views 10 Replies 8 Participants Last post by  Boff
I had a full fresh water tank last night and took a shower. After the shower the fresh water tank ready 80% and the waste water tank read 90%.
I am currently emptying the waste tank as often as the thetford cassette.

Also if I drive with more than a dribble of waste in the grey water tank the van stinks out something chronic. I thought I had fixed a leak a year ago but it is back and I can't see where from.

Any suggestions please?

1 - 11 of 11 Posts
Hi Karl,

When you have a shower put some Daz or Bold washing powder on the floor of the shower and let it go into the waste tank, believe it or not it stops the smell. Only do it every so often and dont wash yourself with it!!

Had the same problem on my boat with the shower sump, used to stink, doesnt now!

It may just be a problem with the gauge ( apart from the smell that is ). Was the waste tank really that full?

I have used soda crystals; about half a packet, dissolved in hot water, say about half a bucket. Pour this down each plug hole into the *empty* waste tank. Drive about for half an hour or more: leave it in overnight then drain it.

I was pointed to this stuff ( very cheap, about 60p a packet I think ) by Keith. the Grommit under another name in a different place. :D

Also try putting all the plugs in the sinks and shower, stops the smell coming up. As for the waste filling fast you may just have a small tank or it is not fully draining down.

On our way home after a trip I empty the waste tanks on site and then half fill each waste tank with fresh water to which I add about a capful of Milton. The sloshing around while mobile cleans all faces of the tanks and leaves absolutely no smell. I just drain the tanks when I get home and the Milton solution keeps moss and algae from my parking area. Afraid I cant help with your leak problem

I do the bio washing powder thing quite regularly and it has stopped the smell being present all the time. It is just when I move with a tank with more than a little in. I am guessing it is due to a leak somewhere but I cannot find it ><

Thinking about it last night and it must be the meter that is wrong as I only get about 4 buckets of waste out when I empty it. I will have to pull the sensor out and check it out :( Shame the access to this is in the van so any smells will have free reign... Yuk

thanks guys.
Most waste tanks are smaller by 20 to 30% than fresh tanks because it is not expected that all fresh water will turn to waste

Water used for tea and coffee for instance

I put all the plugs in, remember many vans do not have U bend traps and I also put some water steriliser or milton or other cleaner down and swill out every so often

Once a year I fill the waste tank full of hot water via a hose at home and then do a half hour run around some bumpy roads and then empty. That moves a lot of gunk

Finally I would not combine the soap powder with hot water and a run over bumps, you will get bubbles, lots of them. What is more don't do it when you are about to shower as it will make the floor of the shower tray slippy and we do not want accidents
after i have emptied the waste tank b4 our jouney home i put washing up liquid into the sink and fill it with water and drain it into the the waste tank then drive home and empty it. we never have any smelly least with the tank anyway.
Hi Gromett,

I know the meter problem from my Eura: The sensor consists of two wires with a certain electrical resistance, and all the dirt in the tank, especially hairs and things like that, has the tendency to collect between those two wires. This creates a partial short-cut and therefore a too high meter reading.

About the nasty whiffs, I could imagine two possible causes:

1. Air pressure difference:
Do you have any windows or - even worse - roof vents open while driving? If yes then the air flow will cause the air pressure inside your van to be slightly lower than outside. This could lead to smells from the waste water or toilet tank to be drawn inside.
Try to drive with all vents closed, ventilating the van via the dashboard fan only.

2. The ventilation/overflow hose:
Count the number of pipes/hoses that connect to the waste tank. There should be one more than you have sinks in your van. This additional hose serves as ventilation and overflow hose, and it should lead through the floor to the outside on a short way. Maybe this hose has gone loose, or leaks.

It could of course also be a combination of the two.

Best Regards,
See less See more
Boff, you are a star. The hose had not come disconnected at the tank end but had pulled up through the hole in the floor so the nasty niffs were going into the underfloor storage area >.<

I am hoping that sorts it :)

Hi Karl!

gromett said:
The hose had not come disconnected at the tank end but had pulled up through the hole in the floor so the nasty niffs were going into the underfloor storage area >.<
Be glad that you have not overfilled the waste tank while the hose was loose! :eek:

Best Regards,
1 - 11 of 11 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.