How to Fill and Use the Fresh Water Tanks in Your Mars Caravan

Your Mars caravan’s fresh water tanks let you camp away from mains water and still enjoy taps, showers (if fitted) and basic washing. Understanding how to fill, use and care for these tanks will make your trips easier and help keep your water clean.

1. Know Where Your Fillers and Tanks Are

Before your first trip:

• Identify the fresh water tank fillers on the outside of your caravan (often marked “Water”).
• Locate the approximate positions of the tanks under the van so you know where they sit relative to axles and weight.
• Check your handover documentation or photos for any isolation valves or selectors linked to the tanks.

2. How to Fill the Fresh Water Tanks

2.1 Equipment You’ll Need

• A clean hose suitable for drinking water (often food grade).
• Any filling adaptors, if required.

2.2 Filling Steps

1. Park the caravan on reasonably level ground.
2. Attach your clean hose to a suitable tap.
3. Insert the other end of the hose into the fresh water filler on the van.
4. Turn the tap on slowly and begin filling.
5. Listen and observe:
   • You may hear water running into the tank(s).
   • When the tank is full, water will usually gurgle near the filler and may overflow slightly from the filler or breather.
6. Turn off the tap once the tank is full and replace the filler cap securely.

Note: Most vans have more than one tank and have separate fillers. Check your specific setup.

3. Switching Between Tank Water and Mains Water

Many Mars caravans can use:

• Tank water via the 12V pump, and/or
• Mains water by connecting a hose directly to a mains inlet.

3.1 Using Tank Water (Pump On)

• Ensure there is water in the tanks.
• Turn on the pump switch (and 12V master if required).
• Open a tap slowly. The pump should start and supply water.

3.2 Using Mains Water

• Connect a suitable hose from the park tap to the mains water inlet on the van (not the tank fillers).
• Turn the park tap on slowly and check for leaks.
• Open a tap inside to confirm water flow.

Some systems use selector valves to choose between tanks. Check your handover notes for the correct positions, or contact Mars support with photos if you’re unsure.

4. Using the Pump Correctly

When using tank water:

• Turn the pump switch ON when you need water.
• Open taps normally; the pump will auto-start and stop as you open and close them.
• If water spits at first, it may just be air in the lines. Let it run until the flow is steady.

When you’re finished using water for a while, many owners choose to turn the pump off to avoid it cycling unexpectedly if a small leak occurs.

5. Basic Water Hygiene Tips

To help keep your water system in good condition:

• Use a dedicated drinking water hose and store it carefully so it stays clean inside.
• After trips, avoid leaving water sitting in tanks for very long periods if you don’t plan to use the van.
• Periodically flush tanks and lines with fresh water:
  • Fill tanks with clean water.
  • Run each tap for a short time.
  • Drain and refill as needed.

Some owners choose to use food-safe tank cleaning or sanitising products from caravan supply stores. Always follow the product instructions and do not use household chemicals that are not specifically recommended for potable water systems.

6. Travelling with Full vs Empty Tanks

Fresh water is heavy, so think about how much you need:

• Full tanks: Provide maximum off-grid range but add weight to the caravan. Ensure you stay within the van’s ATM (Aggregate Trailer Mass) and your tow vehicle’s limits.
• Partial tanks: May be a good compromise if you are only going a short distance before filling again.
• Empty tanks: Reduce weight but mean you must be confident you can refill at or near your destination.

Always consider your weight limits and loading when deciding how much water to carry.

7. What to Do If the Tanks Won’t Fill or Empty Properly

If you experience issues such as:

• Water overflowing prematurely from the filler.
• Tank “full” but very little water at the taps.
• Unusual noises or bubbling when filling.

There may be an issue with:

• Breather lines or vents.
• Tank connections or valves.
• Internal pump or plumbing.

In these cases, take clear photos of the tanks, fillers, hoses and any visible valves and contact Mars Campers support or a qualified caravan repairer.

Summary

Using your Mars caravan’s fresh water tanks confidently comes down to a few basics: know where your fillers and tanks are, fill them with clean water, understand how to switch between tanks if required, and keep the system hygienic.

With a little practice, filling and using your tanks will become just another simple part of your pre-trip routine.