An Easy Guide to Motorhome Toilets, Waste & Water

An Easy Guide to Motorhome Toilets, Waste & Water

In a motorhome, there’s no plumbing to take everything away, or fill everything up again. Your motorhome toilet, waste and water has to be managed on an almost daily basis. This easy guide to motorhome toilets, waste and water systems will explain how it all works.

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It's All About the Loo!

Types of Toilet

The chances are if you have a European motorhome or caravan, you will have Dometic or  Thetford cassette toilet. There are many models but essentially, the cassette holds your toilet waste until you are able to empty it. 

If you are in a camper van, small caravan or older motorhome you may have a Thetford Porta Potti  or other type of portable toilet,  where the bowl and cassette are separated for emptying. This type of portable chemical toilet is also suitable for use in trailer tents. 

The visible part of the toilet may be porcelain and some also now swivel or fold away to save space.  In a modern motorhome or caravan, the flush is linked to your motorhome water system and so flushing water will come from your fresh water tank.  Remember this when thinking about how much water you have and how to conserve it!  Portable camper toilets require manual fill of their flush-water tank.

If you have bought a second-hand or used motorhome with a Thetford toilet, you may want to consider one of their fresh-up sets  which consists of a new cassette and loo seat. We have done this for every motorhome we’ve bought…its just one of those things!

Black Waste

How do you dispose of waste from a cassette or portable toilet?  In an ideal world, you will want to empty your campervan toilet cassette every couple of days; there are variables though, particularly if you are wild camping and find yourself in a remote location.  There is a good video showing how to empty cassette toilets here.

Some people carry an additional cassette for their caravan toilet, which is definitely worth considering if you have space and intend to wild camp. You can read more about managing black waste when wild camping here.  

If you have a cassette toilet (sometimes known as a chemical toilet or elsan toilet) you will require chemicals to help manage the smell as your waste breaks down.

Chemicals for your motorhome or caravan cassette toilet are widely available in most large supermarkets and all camping shops. These are the original Thetford colours but would will find that other brands have mirrored them for ease.

  • Blue – for the toilet cassette, helps mask the smell 
  • Green – as above but environmentally friendly and could be emptied down a normal loo
  • Pink – for the flush-water tank, keeps the bowl clean and smells nice

What about toilet paper for chemical toilets? We generally use middle-of-the-road loo paper, not the cheapest but not quilted. We find that this breaks down without a problem.

Some people don’t like pooing in their van toilet and like to keep their toilet fresh, you can even get bags that line the bowl to poo in! Poo generally breaks down and smells less than wee but will fill up your toilet cassette faster.  

In our experience, black waste points come in many forms and are not all equal; anything from a shiny purpose built service area with automatic flushing to literally an open sewer in the ground and everything in between. Park4Night shows service points on its’ app.

In some badly designed chemical toilet receptacles, if the hole or grating is particularly small and the poo has yet to break down, you may be faced with having to poke it or break it up in some way to get rid of it!  If you suspect this is the case, make sure you have a stick handy for poking; don’t use the hose or you may well end up covered…you have been warned!

SOG Toilet System

If you have a SOG fitted, you will not need chemicals and in fact, defeat the object if you do use them.  

What is a SOG toilet?  It’s basically a 12v fan which vents the toilet cassette whenever you open the blade (the flat plastic piece which separates bowl from cassette) to flush. The vent either comes out the side or top of your van depending on cassette and layout (ideally not into your awning!).  

We would highly recommend a SOG loo (and haven’t been paid to say so!), it’s one of the best accessories we’ve had fitted. You can find out more about them here. This system is not suitable for portable toilets.

Grey Waste

This term refers to all your used water other than toilet waste, so anything from your washing up bowl to your shower water.  Any chemical product you use from washing up liquid, to toothpaste to shower gel ends up in your waste pipe and grey waste holding tank with the waste water. After a while, it starts to break down into the not so nice components it is made up from and boy, does it stink!  

It is particularly noticeable when you have been parked up for a while and then disturb the water when you move; driving along smelling like rotten eggs is one of the unpleasant parts of life on the road.  The chemicals stick to the insides of your tank and continue to deteriorate and even if you use one of the many treatments available, it only masks the issue.  There are some preventative measures you can take;

  • scrape dishes and pans before washing to remove as much residue as possible 
  • if you’re on site, utilise their washing facilities
  • try using eco-friendly soaps and liquids manufactured without chemicals
  • use a strainer basket on your plugholes
  • where possible, empty your grey waste tank daily

The only way to deal with this properly is to periodically clean your grey waste holding tanks. This is a grotty and smelly job but we always feel better afterwards, knowing we are ‘clean’ for a while.  

The best way to manage this is to empty your motorhome waste tank, access a hose with good pressure and literally get your arm as far into your waste tank (if you have access) as possible giving the hose a good spray around. You could use a jet washer but it’s not advisable if access to your waste tank is inside the van. Let this water drain then fill the waste tank to around 20% and add some heavy duty tank cleaner before driving along some mountainous and bendy roads to our next destination, so the whole lot sloshes around before being emptied on arrival.   Then, add this tank freshener to your holding tank regularly, this keeps the worst at bay until your next big clean.

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Fresh Water

Filling Up

Oh wow,  how much water did we waste at home!  When you have a limited amount in your motorhome tank, and you need to shower, brush teeth, flush the loo, cook, wash up, clean your van, make tea, drink and do all the things society generally takes for granted, you realise very quickly just how much you use every time your turn on the taps. 

It is relatively easy though to fill up, either at a site or aire. Look for the dump station signs at garages and supermarkets. Sometimes the water supply is free, the most we have ever paid to fill our tank is €2.  

It is also important to be mindful of not only using your own tank water wisely, but that of the country which is hosting you.  Many parts of southern Europe suffer from acute water shortage; although it’s always available it takes a lot of work and effort to make it so; this should be respected.

Managing your water consumption when you travel not only means you have to fill less often, being less wasteful if also better for the environment. 


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Fresh Water Tips

Follow these tips when managing your fresh water, and it may seem obvious, be mindful of what you are putting in the tank.

  • keep your tank clean and only use potable (drinkable) water.  Even if you don’t intend to drink this water (we advise you don’t), non-potable water can contain bacteria which may sit in your tank and contaminate any potable water you later fill up with.   There is usually a sign by the water tap to tell you whether it’s potable.
  • if you use a water carrier, like this one which is handy as it collapses, only ever use it for potable water.  Mark it so you know, if you have more than one.
  • in Spain, water near the coast may be loosely described as potable but may be de-salinated. We try to avoid putting this in the tank, as we can see debris collecting at the bottom (sand usually).   
  • motorhome water pumps usually have a gauze filter fitted. It prevents tiny bits and pieces of debris from getting into the pump and damaging it.  You should clean this filter periodically.
  • check the arrangements, sometimes the water hose provided (where there is one) may also be the hose used to flush to toilet emptying point…you don’t want poo in your clean water! 
  • if in doubt, use your own roll-flat hose, like this one, or if you really have too, use an anti-bac wet wipe to clean the end of the hose (although I am pulling a face whilst writing that!). Some people prefer a food-grade hose (although we have never found this necessary.
  • use a specialist cleaner for your water tanks on a regular basis, we use this one.
  • you should use water purifying tablets every time you fill up. These are available via Amazon and at all camping shops and will prevent a build up bacteria and virus in your fresh water tanks and destroy any nasties which might make you ill.  
  • try to keep your tank as full as possible as this will also reduce any bacteria growth; bacteria thrive on air.
  • we buy a six pack of 1.5l bottles of water every three months or so and then fill the empties with potable drinking water whenever we can and keep one cool in the fridge.  Bottled water is as cheap as chips in Europe, but if you’re on a tight budget every cent counts.
  • If you’re really concerned then get one of these LifeStraw water filter bottles so that you can drink water from anywhere!
An Easy Guide to Motorhome Toilets, Water & Waste

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