Caravan Plumbing System Maintenance Guide

Properly maintaining your caravan hot water system and plumbing is crucial not only for your RV’s wellbeing but for your good health too. In the hotter more humid months in Australia, the build-up of moisture can be bad enough without with the added worry of additional leaking. If you spend any of the colder times of year in your caravan hot water is essential. This caravan plumbing system maintenance guide will help with most caravan water heating setups, whether you run caravan gas heaters, your system is electric or your caravan’s hot water system is a gas-electric combo.

Caravan Plumbing System Maintenance

Toilet Tanks

Toilet tanks can be problematic if not properly maintained. They should be cleaned regularly to ensure they’re free of bacteria and algae. Flushing out water with a caravan specific cleaner (or white vinegar/bicarbonate of soda) through the grey and black water tanks regularly will help. It is important you don’t use domestic cleaners which contain bleach as these will erode the seals. Fill the grey water tank with a mixture of water and cleaner and let it stand for a few hours, then check for leaks. The black tank can be cleaned with clean water. Leaving the wastewater tanks open to dry also helps kill bacteria.

Pumps and Heaters

Whether you have a submersible and diaphragm pump, it is common for pump seals to erode over time, so if you spot any leaks in your system these will need to be replaced. Water heaters also need to be regularly cleaned and flushed out. Mix equal parts water and white vinegar, add to the tank, and then heat to maximum temperature before cooling down. Then simply empty and rinse with clean water.

Water Tanks

The best way to ensure that your freshwater tanks remain bacteria-free is to regularly flush them out with a cleaning agent. To rinse them out, make sure the tank is drained empty, add the water and cleaning agent to the tank, cover and simply go for a drive, which will get the water moving around the tanks. Then drain the tanks again and rinse. For drinking water tanks, use sodium or calcium hypochlorite rather than stabilized chlorine to keep from contaminating

Caravan Plumbing System Maintenance

Moisture Meter

Damp causes mould and mildew, both of which are known to be damaging to human health. Moisture also, of course, contributes to rust, so it is pretty terrible for your motorhome too. A moisture meter can be used to take a reading of the amount of moisture in your caravan. A reading of anything above 15% should give you cause for concern, and anything above 25% this is enough to structurally damage your RV.


Identify where the ventilation slots are on your caravan and make sure there is nothing blocking these. We would recommend you keep all ventilation free of blockage as caravans, motorhomes, fifth wheelers, or indeed any small space with a water tank needs an outlet, or mould and rust related damage will occur rapidly. Cleaning and vacuuming these regularly is recommended also.

Pump Has Stopped

If your pump has stopped working, the causes of this are likely to be quite easy to identify and fix. The first place to check is your motor. If your motor seems to be running well, check the power source with a 12V tester.

If all of this seems to indicate there is no problem, you may have an airlock, which is where bubbles of trapped air stop the flow of water and stopping your pump from working. If you have a manual pump, use this to drive the air out of the system and this should solve the problem.


It is important to clean up any spillages, no matter how minor they seem, as it does not take much standing for bacteria and mould to develop and as we have discussed this can be very detrimental to your health if left unchecked.

Hot Water Heater Not Working

If you’re having caravan hot water system problems you might find that your hot water system does not work constantly, and if you’re on the road travelling Australia is obviously problematic. You may even find that your hot water system stops completely. At the end of this article, we discuss how to troubleshoot these problems.

Plumbing Leaks

Even with regular checks and maintenance, over time you may still find that your system develops leaks. The good news is that these are normally fairly easy to identify and deal with. The easiest way to spot water leaks in a caravan is to check the seals for any black matter. The seals on caravan water systems are made of plastic can deteriorate over time and rot away. Luckily they are not too difficult or expensive to replace.  

Shower Resealing

If your shower is not properly sealed, then damp can seep out into the structure of your caravan creating a body of stagnant water inside your vehicle, contributing to mould and rust related problems. You should regularly reseal the areas around the shower so they remain watertight. If there is, however, already a damp smell in your shower area, then you may already have a problem.

Too Much Humidity (Get a Dehumidifier)

Again, even if you take great care of your water system and follow all of the tips above, it is nearly impossible to remove all moisture from your caravan. Keeping a dehumidifier on board and running this periodically is a great idea.

Erratic Water Flow

If your water flow is erratic or irregular, there is a good chance that somewhere in your system something is blocked, a pipe is bent or the pump battery is depleted. Installing an accumulator or surge damper should resolve the problem.

Caravan Hot Water System Troubleshooting

If you have problems with your hot water system and your hot water is irregular or stopped completely, here are three tips to identify what might be wrong with the hot water system for caravan owners.

Check for Gas or Electrical Supply Issues

The most common cause is a fault in the gas or power supply. If you run on gas, check your other gas appliances are working. If they are not, check the main regulator pressure. It should ideally be 2.8kPa. If this is all fine, there could be a physical obstruction in the pipe. Insects can get in here and cause obstructions, as can an excess carbon build-up. A jet of compressed air can remove both. See other Benefits Of Installing Gas In Your Caravan in this post.

For electric hot water systems, check your other electrical appliances. If they are not working, you may have a blown fuse.

Check the Water Supply Line

Turning off your hot water system, and the water pump. The switches for both should be under your kitchen sink. Then, check the position of the water heater bypass lever to ensure it is not set to ‘bypass’.  In the ‘normal’ setting, turn on a tap to check that the flow of water is about the same in both hot and cold positions.

Check the Thermostat and Heating Element

If neither of the above steps identifies a problem, you may have a broken thermostat. For gas and electric hot water systems, if your hot water on the gas setting but not electric, the heating element could be broken. Luckily, both of these problems only require a part replaced and this is fairly easy and cheap.

Looking to ensure your caravan plumbing system is up to scratch?

Unfortunately, if none of this works you will need to call in a professional to give your system a thorough check. Luckily, most caravan plumbing system repairs can be completed at reasonable prices. Check out our range of folding camper tables and caravan hot water systems here for maximum comfort while caravaning!

Updated 18/09/2023

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