# Smelly water tanks Dethleffs Help



## Vinney (Feb 23, 2010)

Hi All. Summer is here I think. We are heading of on hols toward spain the sun heat and a smelly water tank. How to deal with this. I have tried the biological powder, the stuff u buy in motor home shop, I have empty tanks. What have I missed. Also it is not just my van. Before we bought ours we rented one the exact same new (Ours 5 years old) and it had same problem. It only happens when we move the van. 
Can I seal the tank or run a vent from it. Our van is a Dethleffs a7870 tag with tanks inside great for winter & skiing but come the summer they cook and then smell. 
Help Ta in advance  :


----------



## bognormike (May 10, 2005)

the problem lies with the fact that there are generally no U bend traps in the drains, so the smell of the festering waste in the tank comes up the pipes. we try to flush out regularly, but it's still a problem. We always make sure that all the plugs are in the sinks / shower when travelling, because you always get a waft of smelly water when driving along if you don't.!! Try to avoid washing food waste down the kitchen sink, and empty the waste tank regularly.


----------



## Zepp (May 14, 2009)

Vinney said:


> Hi All. Summer is here I think. We are heading of on hols toward spain the sun heat and a smelly water tank. How to deal with this. I have tried the biological powder, the stuff u buy in motor home shop, I have empty tanks. What have I missed. Also it is not just my van. Before we bought ours we rented one the exact same new (Ours 5 years old) and it had same problem. It only happens when we move the van.
> Can I seal the tank or run a vent from it. Our van is a Dethleffs a7870 tag with tanks inside great for winter & skiing but come the summer they cook and then smell.
> Help Ta in advance  :


I guess your talking about the waste water tank , we use milton or Tank Fresh in ours.

Paul & Lynne


----------



## Vinney (Feb 23, 2010)

Yes Have tried flushing tanks regulary will try the plugs again but this didnt make much of a difference also there are traps on our pipes not U bends. Appreciate the advice. Ta.V


----------



## seanoo (Mar 31, 2007)

hi vinney, i normally go to aldis or lidle and buy 4 or 5 big bottles of the cheapest coke and pour them down the plug holes in my van, then go for a good drive to shake it all up! you'd be surprised at all the gunk that comes out. all the best sean


----------



## PeteandMe (Sep 19, 2010)

Waste pipes need one way valves fitting to them.


----------



## seanoo (Mar 31, 2007)

or just leave plugs in the plugholes


----------



## tramp (May 25, 2005)

Hi vinney..
those tanks should not smell at all...the traps have a twist bottom to clean them and remove hair etc.

Also they will contain small amount of water to stop smell coming back from tank into vehicle hab side.

You have to disenfect the tank and pipe sytem ... our dethleffs never had this problem in any .weather


----------



## greenasthegrass (Oct 27, 2007)

Ours has never smelt either but we do the cheap coke once a year, always travel with the plugs in and empty as soon as possible. Try the coke thing first Morrisons 4 litres should do it.


Regards

Greenie


----------



## quickgetaway (Jun 13, 2006)

Hi
we used to have a big problem with this but now looks to be a lot better. This is what we do:-

Keep the plug in the shower.
Do not put any food waste including liquids down the sink - wipe plates and pans before washing them.
When moving the van - empty the waste tank before you go, then close the valve (some people drive with it open). Put cleaner down all the plugs (we use the Elsan waste tank cleaner) and also some hot water (about half a washing up bowl full).
Whilst driving it will slosh around the tank and hopefully clean all the sides and top with the motion.

For the fresh water tank we use about half a cap of Milton addded to the water. We do not drink the water from the fresh tank but use separate water jugs that sit in the fridge.

Hope this helps

John


----------



## levoyden (Feb 25, 2008)

Our waste tank is fine!!!!! its our Fresh water tank that caused us a lot of grief. We tried Milton and tank after tank of Fresh water. We were then advised by Hayes and LeVoyageur to use Bleach, 1ml per litre of water.. The fresh water tank is better, but the waste tank is like or better than the fresh water tank. (it was drained 4 times after the Bleach)
Den

,Ps I know its not directly linked to your problem, but the biproduct of me cleaning the fresh water tank resulted in a ultra clean waste tank.


----------



## rocky58 (May 11, 2005)

In my dethleffs waste tank there is a red inspection hole which will unscew.I put hosepipe in and flush it out ,a lot of gung around screw part of inspection hole thread which smelt.


----------



## zappy61 (May 1, 2005)

levoyden said:


> Our waste tank is fine!!!!! its our Fresh water tank that caused us a lot of grief. We tried Milton and tank after tank of Fresh water. We were then advised by Hayes and LeVoyageur to use Bleach, 1ml per litre of water.. The fresh water tank is better, but the waste tank is like or better than the fresh water tank. (it was drained 4 times after the Bleach)
> Den
> 
> ,Ps I know its not directly linked to your problem, but the biproduct of me cleaning the fresh water tank resulted in a ultra clean waste tank.


Hi Den,

Sorry to hear of your problem you might like to see my article 
Grahamhere and thread here. If I can be of further help let me know.

Graham


----------



## rosalan (Aug 24, 2009)

I know it sounds pretty obvious but always close the grey water tap when travelling. In some 'dry' (no "P" trap) systems, the air pressure can be blowing up the outlet, through the tank and into the van. I used to always leave mine open to make sure I was carrying no extra unwanted grey water, so that is how I learnt.  
Alan


----------



## Vinney (Feb 23, 2010)

Thanks for the advice. I never thought of the fresh water tank as been the possible cause. I don't think it is though.
I will try all options coke milton and bleach. I will open the tank and have a look. Tried this before but cap wouldn't open but will try again. 
Is there a vent on the tank I assume there is one as you must displace the air as the tank fills with waste water. Where is it and could this be the culprit.
Ta Again.
V


----------



## DJMotorhomer (Apr 15, 2010)

Hi

When we have finished at a site we always open the cold taps and empty all the water from the clean tank into the grey waste tank. Once that is full we empty both tanks at the dump station. 

We get no smells

Hope that helps


----------



## zappy61 (May 1, 2005)

*water tank*



Vinney said:


> Thanks for the advice. I never thought of the fresh water tank as been the possible cause. I don't think it is though.
> I will try all options coke milton and bleach. I will open the tank and have a look. Tried this before but cap wouldn't open but will try again.
> Is there a vent on the tank I assume there is one as you must displace the air as the tank fills with waste water. Where is it and could this be the culprit.
> Ta Again.
> V


Hi Vin,

The breather pipe doubles as the overflow pipe and is normally on the side of the tanks somewhere. I wouldn't use household bleach for the freshwater as it contains surfactants and may cause problems. Milton is difficult to get the dose strength right,and can lead to taste problems.

Regards,

Graham


----------



## Vinney (Feb 23, 2010)

The breather pipe is the one I need to find. I will get into the van Tuesday and check it out. I bet that is the problem. I will let u know how it goes. 
Ta. 
V


----------



## zappy61 (May 1, 2005)

Vinney said:


> The breather pipe is the one I need to find. I will get into the van Tuesday and check it out. I bet that is the problem. I will let u know how it goes.
> Ta.
> V


Hi Vin,
If you find the breather pipe the system will still need cleaning to eliminate the source of the problem.

Graham


----------



## PeteandMe (Sep 19, 2010)

Some tanks don't have a dedicated pipe for the overflow/breather. Instead of series of holes that are part of the tank molding. These will be around the top of the tank. Easily found if no dedicated pipe is found by flooding the tank and looking for the dribbles.


----------



## Vinney (Feb 23, 2010)

I tried to over fill tank to see if there was a external over flow pipe. Guess what there is not! Had water inside the van. This has to be where the smell is coming from all I need to do is find it. The access cap to the tank has been silaconed down. I will be able to open it tomorrow. 
I reckon if I can set up a overflow pipe, clean tanks as advised and vent it outside that should sort my problem.
V


----------



## PeteandMe (Sep 19, 2010)

So if there is no overflow any water going into the tank has to vent to somewhere. That will be back up through the bathroom sink shower or the kitchen sink depending on which tap is running. Result will be smells will be forced into the van. The other effect could be that water will be slow to drain.


----------



## Spacerunner (Mar 18, 2006)

I doubt if the grey water tank will need an air vent. It would most probably use the drain pipes in the system for air balance.

Our Chausson has traps on all plugholes. They appear to be standard size so maybe retro fitting these may help.

Although the waste water niffs a bit when draining, same smell as domestic drains, we dont get any smell in the interior.

Another way to prevent smell building up is not to leave waste tank drain in 'dribble mode'. Although this lets the water out it will trap solids and cause a mucky tank.


----------

