How to clean the water tank in your camper van properly

A natural slimy layer called a biofilm builds up over time in the camper van’s water tank. This (completely normal) layer is caused by micro-organisms, such as algae, bacteria and fungi, which adhere to the tank’s inner walls and pipes. However, the biofilm is also the perfect breeding ground for harmful bacteria and germs. Taste suffers also if limescale deposits accumulate in the water system.

Unfortunately, you cannot always recognise impurities with the naked eye. Even if the water is clear, it may be contaminated with germs. But since you need it for drinking, brushing teeth and cooking in the camper van, regular cleaning of the water tank is a must. This is the only way you can prevent dangerous germs from multiplying.

You should clean your water tank at least twice a year in any case. Once at the beginning of the season and again at the end. This means you will have fresh, clean water when you set out on your holiday in the camper van. And afterwards you can prevent the accumulation of bacteria if your camper van is stationary for a long time.

Even if you winter-proof your camper van, you should still clean the water tank. And even if you use your vehicle throughout the year, you should clean your water tank at least twice a year. Deposits and impurities won’t stand a chance then.

Various tank cleaners are also available for cleaning the camper van’s fresh water tank. But you can also use ordinary household remedies such as citric acid.

Whichever option you choose, just follow these instructions and nothing can go wrong:

• The cleaner must be compatible with the material of the water tank and the pipes.
• Use a single cleaning agent and never mix several together.
• Observe the recommended exposure time.

Special cleaners

You can buy specially prepared tank cleaners for camper vans and caravans. There are liquid cleaners that are poured directly into the tank or powder that you have to first dissolve in hot water.

These cleaners are effective at removing the biofilm and other deposits in the water tank, without damaging the materials. They contain hydrogen peroxide, chlorine dioxide, active oxygen or fruit acids. Coloured cleaners are best as you will then be able to detect residues from the cleaning agent in the tank.

Household remedies

If you prefer to use natural products that are also inexpensive to buy, then household remedies are a good choice for you. You don’t need to use a special cleaner to clean and disinfect your water tank. However, make sure you find out before use if your remedy is also suitable for camper vans.

Citric acid is particularly environmentally friendly, removes stubborn limescale deposits and dissolves the biofilm. But beware: do not heat citric acid as it can otherwise leave behind residues that can no longer be removed. The correct mixing ratio is also important. The amount of acid you need varies depending on the degree of contamination, calcification and the size of the tank. If the tank has a capacity of 100 litres, as a rule of thumb mix a solution containing four litres of water and five to ten heaped tablespoons of citric acid.

Vinegar essence is very effective against limescale, but also quite aggressive and therefore only suitable for the inside of the tank, though not for cleaning seals.

Incidentally: chlorine cleaner is not recommended. Not only does it smell unpleasantly strong, it can also damage the material of the pipes. Similarly denture cleaner; although it is antibacterial, it can leave behind residues that can block pumps and pipes.

The process varies depending on which cleaning agent you use. We will describe in general here what you should do to clean the water tank.

For your own safety, always carefully read the usage instructions for the cleaning agent. You will find information here concerning dosage and exposure time. Remember also to wear gloves and safety goggles when using chemical cleaners. Should you or someone else accidentally swallow some of the cleaner, seek medical assistance immediately. For this reason, small children should not be present when you are cleaning the tank.

Before cleaning:

First things first: the right location. It is best to park in your own private parking place or at a campsite with supply and waste disposal facilities. You should not clean your tank in a public car park because of the large amount of water.

Switch off the hot water boiler in your camper van. Then empty the tank. To do this, open the valve at the bottom and let the water drain completely. Turn on all the taps in order to flush the pipes. Incidentally, you can digitally monitor the fill level of the water tank in the California camper van at any time.

Step-by-step instructions for a clean water tank

1. Brush the surface of the tank thoroughly by hand: wipe the inside walls of the tank thoroughly by hand to dissolve the biofilm. The cleaning agent will also be more effective as a result. Use a thin bottle brush or toilet brush for the pipes and narrow edges and angles in the tank.
2. Pour in cleaner: mix the tank cleaner according to the manufacturer’s instructions and pour it into the tank through the service opening. Then fill the tank about a third full with water.
3. Flush the pipes: switch off the boiler and open all taps in the camper van for approx. 30 seconds to distribute the cleaning liquid in the water system.
4. Allow to take effect: allow the cleaner to take effect according to the instructions (from a few hours to a day depending on the agent and degree of contamination).
5. Empty the tank: open all taps again to drain the mixture into the grey water tank. Leave it to take effect there for a while and then empty the waste water tank somewhere suitable.
6. Final cleaning: finally flush the water tank and the pipes thoroughly with fresh water to remove any residues.
7. Ready: your water tank is clean and can be filled again.

To prevent contamination in the water tank in the first place, there are a number of preventive measures you can take. Replace the fresh water regularly. If you have filled your tank with tap water, if suffices to replace it weekly. If your water is from a river or lake, it is best to replace it every couple of days. You should ideally use a hose to do this. It is more hygienic than filling the tank with a watering can. Make sure that the hose is fitted securely to the filler neck and use an adapter if necessary. This means that nothing can fall out.

If you know that your camper van will be stationary for a longer period, then consider emptying the water tank to prevent germs from forming. This also protects against frost damage if you are not planning to go camping in winter.

Despite precautionary measures, a stubborn biofilm forms in the water tank after a while: regular cleaning is therefore particularly important for water quality.