Practical Tips for UK Fifth Wheel Owners: Water, Tanks & Toilet
- kenworth9
- 13 hours ago
- 4 min read
Water, Setup & Everyday Maintenance
Whether you’re new to 5th wheel camping in the UK or you’ve been touring for years, there are a number of simple, practical habits that make life easier, safer and far less stressful.
These are not theory-heavy tips or things buried in manuals. They’re the kind of real-world lessons most people only learn after making a mistake, or after someone takes the time to explain them properly. This guide brings some 5th wheel lessons relating to water, tanks and toilet.
Freshwater Tank Tips All UK 5th Wheel Owner Should Know
When refilling your freshwater tank after it has been drained, don’t immediately close the drain valve and fill straight up. Leave the freshwater drain valve open to begin with and allow a small amount of water — around a gallon — to run out before closing it.
This helps flush any stagnant water sitting in the pipework and clears out sediment that may have settled in the bottom of the tank. It’s particularly useful after storage or longer gaps between trips, which are common with UK touring.
We have a post you can check if you're looking for advice and products to keep your drinking water clean, fresh and safe to drink, take a look here.
If you’re connecting to mains water at a campsite, the same principle applies. Once connected, run your taps and shower for 15–30 seconds to clear old water from the system before normal use.
Travelling With Water Onboard: Think About Weight
Some owners like to travel with a small amount of water in the freshwater tank so they can use the toilet or wash hands on travel days. Also, carrying a little water in the black tank is great for helping prevent the dreaded poo mountain. Carrying water can be useful, but always consider your total weight.
Water weighs 1 kilo per litre, so even partially filled tanks can add weight quickly. Before travelling with any water onboard, it’s important to know your weights limits. For some UK setups, carrying a full tank on the road isn’t realistic.
A sensible approach for some is to carry only a small amount for basic use while travelling — or none at all — and then fill the tank once pitched, where weight limits are no longer a factor in the same way.
Talking of 'Poo Mountains'...
Toilet blockages can happen, especially if you have children on board or guests that don't know the limitations of the toilet system in a 5th wheel or caravan or motorhome for that matter. We have developed a fool-proof method for getting rid of any blockages and have a video that illustrates this. We suggest you keep the following in your belly locker: 4' of pex pipe (plastic water pipe), gloves, maybe some goggles. Watch our video to see how it's done.
Mains Water Connections and Protecting Your Plumbing
UK campsite water pressure can vary significantly from site to site. Every UK fifth wheel owner should be using a water pressure regulator when connecting to mains water to protect internal pipework and appliances from excessive pressure.
Products worth looking at include: Basic inline regulator from Valterra: link to Amazon
Adjustable RV water pressure regulator with gauge: link to Amazon
Always use a food-grade potable water hose rather than a standard garden hose. It’s a small detail, but it makes a difference to taste (especially if its hot outside), water quality and long-term system health. Remember, your system's health relates to your own - so make sure it's A-OK.
The Water Filter Many Owners Forget About
Aftermarket water filters get a lot of attention, but many fifth wheels already have a built-in sediment filter on the water pump. Its job is to catch grit or debris before it damages the pump’s internal seals and diaphragm.
These filters usually unscrew by hand and can be rinsed under the tap. Check them a couple of times a year and replace them if the mesh shows signs of damage or corrosion. It’s a simple bit of maintenance that can save a costly pump replacement later on.
A Cleaner, Safer Way to Empty Your Waste Tanks
The usual advice is to dump the black tank first and the grey tank second — and the logic behind that still holds. However, there’s a small improvement that can make the process safer and cleaner.
Use the grey – black – grey approach.
Briefly open a grey tank first to confirm your hose connections are sealed properly. If there’s a problem, it’s far better to discover it with grey water than black. Once you know everything is secure, dump the black tank, then finish with grey water to rinse the hose.
Tank Sensors Can Be Unreliable, That's Pretty Normal
If your tank sensors give inconsistent or incorrect readings, you’re not alone. This is extremely common across all RV types, including fifth wheels.
Debris and toilet paper can stick to the sensors and cause false readings. Most owners learn to treat them as rough guides rather than precise measurements. It’s frustrating, but normal — and not something to worry about as long as you manage tanks sensibly.
Campsite Water as Backup — Without Carrying Extra Weight
Once pitched, filling the freshwater tank fully makes sense. It gives you a backup if campsite water pressure drops or the supply is interrupted, and it allows you to supplement low pressure using the built-in 12-volt pump.
The key is timing: fill once you’re set up, rather than carrying unnecessary weight on the road.
Final Thoughts for UK Fifth Wheel Owners
None of these water and tank tips are complicated or expensive, but together they can make a big difference to your RVing experience. Apply them in the context of your own vehicle limits, adapt them to how you travel, and build routines that suit your setup.
Being prepared helps make fifth wheel touring in the UK less like hard work and more like the leisure-pleasure you look forward to.
Take a look at our YouTube channel for video playlists that provide help, advice, and the real world experience of other fifth wheel owners.
CCRV on YouTube:
Comments