Caring for your motorhome: Cleaning the water tank

    A clean water tank is essential for safe and hygienic water supply when you’re on the road. To ensure a consistently clean drinking water supply, tanks and pipes must be cleaned regularly. We show you how to clean the water tank in your motorhome and what to take into account. We’ll also introduce you to an alternative to chemical cleaners from specialist retailers.

    Why should you clean the water tank in your motorhome regularly?

    Over time, not only does limescale build up inside water tanks, but so does what’s known as a biofilm. Biofilm forms around microorganisms and provides an ideal environment for bacteria. That’s why regularly cleaning the water tank in your motorhome is important. However, it’s not possible to completely prevent the formation of such a biofilm in a wet environment. It develops from particles in drinking water, plasticisers from plastic components, and limescale deposits.

    How often should the water tank be cleaned?

    As a general rule, it’s advisable to clean the water tank in motorhomes at least once a year. Even better is to clean the tank before and after each season. At the latest, if the water starts to smell unpleasant or taste unusual, it’s essential to clean it.

    Tip: New to camping? To make sure you don’t forget anything before your trip, it’s best to create a checklist. Be sure to include cleaning the water tank as part of it.

    Are there alternatives to chemical cleaners?

    Specialist retailers offer a range of professional cleaning products for cleaning motorhome water tanks. Their effectiveness is usually based on substances such as chlorine dioxide, active oxygen, or fruit acids. It’s essential to follow the manufacturer's instructions when using these products to prevent subsequent contamination of the drinking water.

    Caution: Wear gloves when cleaning the water tank to prevent cleaners from coming into direct contact with your skin. Never mix different cleaning agents. Chemical reactions can produce harmful gases.

    Care should also be taken with some household remedies. Vinegar essence dissolves limescale and is antibacterial, but it can damage seals. Denture cleaning tablets have an antibacterial effect but may leave residues that could damage the pump. If you’re looking for an alternative to clean your water tank in a motorhome, we recommend using citric acid.

    Cleaning the water tank with citric acid

    Step-by-step instructions

    Step 1: Empty the water tank

    First, drain all water from the tank and boiler. Open the inspection cover and all taps.

    Step 2: Manual cleaning

    If you want to clean the water tank in your motorhome, you first need to manually break up the biofilm inside, as already mentioned. This is important, as biofilm protects bacteria from external influences such as temperature and pH fluctuations, or the effects of chemicals. If the biofilm is fully intact, cleaning agents may not be effective.

    For manual cleaning, first use a damp sponge to dissolve limescale and other deposits, then scrub the tank out with a brush. Remove all seals and caps and clean them with a sponge as well. You should also clean the water pipes as far as possible – thin pipe brushes, like those used for cleaning aquariums, are ideal for this. Afterwards, close the water tank and boiler again.

    Step 3: Preparing the citric acid

    Dissolve the citric acid powder in warm water. For a water tank with a capacity of 100 litres, you’ll need four litres of water and five to ten heaped tablespoons of citric acid. Adjust the quantities accordingly to your tank.

    Step 4: Cleaning the water tank and pipes

    To clean the water tank and pipes in your motorhome, pour the fully dissolved citric acid into the tank via the inspection or filling opening. Important: The citric acid powder must be completely dissolved. Then fill the tank and boiler with fresh water and open the taps for about half a minute to rinse the whole system. Close the taps again and let the citric acid work for at least 30 minutes. After the exposure time, open the taps again and let the water run until the tank is completely empty.

    Tip: Although citric acid is fundamentally harmless, it’s recommended to empty the waste water tank at a dump station.

    Step 5: Rinsing with fresh water

    Finally, refill the water tank with fresh water and let it run through the system until the tank is empty. Then leave the inspection and drain covers, as well as the taps, open for a while so the water system can dry.

    References

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