Your caravan’s water system is the lifeline of your big lap adventure. Regular maintenance prevents costly breakdowns, ensures safe drinking water, and keeps you self-sufficient in remote locations. This guide walks you through the essential maintenance tasks for tanks, pumps, and filters — everything you need to keep water flowing reliably for months on the road.
Most caravan water system failures happen gradually, giving you warning signs if you know what to look for. The key is staying ahead of problems with routine maintenance rather than waiting for emergency repairs in the middle of nowhere.
Step 1: Inspect and Clean Water Tanks
Start your maintenance routine by draining and inspecting your fresh water tank. Most caravan tanks need cleaning every 3-6 months depending on water quality and usage. Dirty tanks breed bacteria and create foul-tasting water that makes your trip miserable.
Drain the tank completely: Open all taps, run the pump until it cycles rapidly (indicating empty tank), then switch off the pump. Remove the inspection hatch if your tank has one, or work through the filler opening.
Visual inspection: Look for cracks, discolouration, or biofilm buildup on the tank walls. Small hairline cracks often appear near mounting points or where pipes connect. Black or green slime indicates bacterial growth that needs aggressive cleaning.
Clean the tank interior: Mix 1 cup of white vinegar with 4 litres of warm water. Pour this solution into the tank and let it sit for 2 hours. The acetic acid breaks down mineral deposits and kills most bacteria. For stubborn buildup, use a long-handled brush to scrub accessible areas.
Add 20-30 aquarium pebbles to your tank after cleaning. They act as natural scrubbers during travel, keeping the tank walls cleaner between services.
Check tank fittings: Examine all connections for leaks, corrosion, or loose fittings. The tank outlet, level sender, and overflow connections are common failure points. Replace any corroded fittings immediately — they only get worse on the road.
Step 2: Service Your Water Pump
Water pumps work hard on a big lap, cycling dozens of times daily. Regular servicing prevents the dreaded pump failure that leaves you without pressurised water. Most quality pumps need attention every 6 months or 500 hours of operation.
Remove and disassemble the pump: Switch off power and disconnect electrical connections. Remove the pump from its mounting and carefully separate the pump head from the motor housing. Most pumps use 4-6 screws around the perimeter.
Inspect the diaphragm: The rubber diaphragm is the heart of your pump. Look for tears, holes, or hardening around the edges. Even small perforations cause pressure loss and erratic operation. Replace the diaphragm if you find any damage.
~$45
Clean the valve assembly: Remove the intake and discharge valves (usually spring-loaded plastic discs). Clean both the valve surfaces and their seats with warm soapy water. Mineral deposits here cause poor flow and pump cycling issues.
Check electrical connections: Corrosion at the pump terminals causes voltage drop and premature failure. Clean terminals with electrical contact cleaner and apply dielectric grease to prevent future corrosion.
Never run your water pump dry for more than 30 seconds. Dry running destroys the diaphragm and can seize the motor. Always ensure adequate water supply before testing.
Step 3: Replace Water Filters
Clean filters are essential for safe drinking water and protecting downstream components. Most caravan systems use inline filters that need replacement every 3-6 months, depending on water quality and consumption.
Locate all filters in your system: Typical setups have a sediment filter after the tank outlet, a carbon filter before the taps, and possibly a third filter for drinking water. Map your system so you don’t miss any filters during maintenance.
Replace sediment filters first: These catch dirt, rust, and debris from tank water. A clogged sediment filter reduces flow throughout the entire system. Turn off the pump, relieve system pressure by opening a tap, then unscrew the filter housing.
Install carbon filters: Carbon filters remove chlorine, taste, and odour from water. They should be replaced when water starts tasting “off” or every 6 months, whichever comes first. Soak new carbon filters for 10 minutes before installation to remove air bubbles.
Write the installation date on each filter with a permanent marker. This simple step prevents confusion about replacement schedules, especially on long trips.
Prime the filter system: After installing new filters, run water through the system for 2-3 minutes to flush air bubbles and carbon fines. The first water may appear cloudy — this is normal and clears quickly.
Step 4: Check Pressure System Components
Your caravan’s pressurised water system depends on several components working together. Regular checks prevent pressure loss, pump damage, and water waste from hidden leaks.
Test the accumulator tank: The accumulator smooths pump operation and reduces cycling. Press the valve stem on top — you should hear a brief hiss of air. If water comes out instead of air, the internal bladder has failed and needs replacement.
Inspect pressure relief valves: These safety devices prevent over-pressurisation but can stick open or closed. Remove the valve cap and manually lift the relief lever. Water should flow freely when lifted and stop completely when released.
Check all pipe connections: Look for white mineral deposits around fittings — a sure sign of slow leaks. Tighten loose connections, but don’t over-tighten plastic fittings. Replace any cracked or deteriorated O-rings immediately.
Calibrate pressure switch: Most pumps cut out at 40-60 PSI. If your pump runs constantly or provides weak flow, the pressure switch may need adjustment. Use a pressure gauge at the nearest tap to verify system pressure.
Step 5: Sanitise the Entire Water System
Regular sanitisation kills harmful bacteria and prevents biofilm buildup throughout your water system. Sanitise every 3 months or after filling from questionable water sources.
Prepare sanitising solution: Mix 2 tablespoons of unscented household bleach with 4 litres of water. This creates a mild chlorine solution that kills bacteria without damaging system components. Never use scented or colour-safe bleach.
Fill and circulate: Pour the solution into your tank and fill with fresh water. Turn on the pump and open each tap in sequence until you smell chlorine at every outlet. Don’t forget the hot water system, shower, and outdoor taps.
Contact time: Let the chlorinated water sit in your system for 4-6 hours. Overnight is even better for thorough disinfection. The chlorine needs time to penetrate biofilms and kill embedded bacteria.
Fill your kettle with the sanitising solution and boil it. This sterilises your kettle’s interior and element, which often harbour bacteria that contaminate drinking water.
Flush thoroughly: After the contact period, drain your entire system and refill with fresh water. Run all taps until the chlorine smell disappears completely. This usually takes 2-3 full tank flushes depending on system size.
Step 6: Test System Operation
After completing maintenance, thoroughly test your water system to ensure everything works correctly. This final step catches any problems before you’re relying on the system in remote locations.
Pump performance test: Open a single tap and time how long it takes to fill a 1-litre container. Most 12V pumps should deliver 10-15 litres per minute at full pressure. Significantly lower flow indicates pump wear or system restrictions.
Pressure hold test: Close all taps and note the system pressure. Wait 30 minutes — pressure should remain stable. Gradual pressure loss indicates a leak somewhere in the system that needs investigation.
Check all outlets: Test every tap, shower head, and water connection point. Look for leaks, poor flow, or unusual noises. Pay special attention to connections you disturbed during maintenance.
Hot water system test: If your system includes hot water, run hot taps until water reaches full temperature. Check the pressure relief valve on your hot water service and ensure the tempering valve delivers safe temperatures.
Common Maintenance Mistakes to Avoid
These frequent errors cause expensive repairs and system failures. Learn from others’ mistakes instead of making them yourself.
Using the wrong cleaning products: Harsh chemicals damage rubber seals and plastic components. Stick to vinegar, mild soap, and approved sanitising solutions. Avoid bleaches with additives or cleaning products containing ammonia.
Over-tightening fittings: Plastic pipe fittings crack easily when over-tightened. Hand-tight plus quarter turn is usually sufficient. Use thread sealant rather than excessive force to prevent leaks.
Ignoring minor leaks: Small drips become major failures on rough roads. Fix leaks immediately rather than hoping they’ll improve. Water damage to your caravan’s structure costs thousands to repair.
Running pumps without priming: Always ensure your pump has water supply before testing. Dry-running destroys diaphragms and can seize pump motors within minutes.
Mixing old and new filters: Replace all filters at the same time for optimal performance. Mixing old and new filters creates uneven flow and reduces overall filtration effectiveness.
- Service your water system every 3-6 months to prevent costly failures on the road
- Clean tanks with vinegar solution and inspect for cracks or biofilm buildup
- Replace pump diaphragms and valves at first signs of wear or pressure loss
- Change filters regularly and mark installation dates for easy tracking
- Sanitise the entire system quarterly using proper bleach concentrations
- Test system performance after maintenance to catch problems early
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