Camper van water systems explained

Most of us don’t worry about water at home. We get a mains supply with enough pressure so when we turn a tap, fresh drinking water flows. It’s all different in a camper van. We need to store and carry a supply of freshwater, pump it to the taps and make sure we can re fill when we’re running low. We need to dispose of dirty water and might even want to heat a little for an occasional shower. In this post, we’ll walk you through each component of camper van water systems design.

Camper van water systems - camper van water system diagram

Limiting the amount of water we carry in our camper van

As with most decisions in a camper van conversion, the design of the water system is full of compromises. Consider these fundamental points:

Cost: water tanks don’t come cheap so the more water you carry, the more it’ll cost to fit.

Space: water takes up a fair amount of space. Each 100 litres of water needs 0.1 cubic metres of storage so you’ll need to get creative with where to fit the tanks.

Weight: water is pretty heavy at 1 kg per litre. Vans have a gross vehicle weight and it’s not legal to exceed it. And anyway, the more weight we carry, the worse our fuel consumption.

Because of the cost, weight and storage implications, we try to carry as little water as we can, while still having enough to stay off grid for a few days.

How much water do we need to carry in our camper van?

Water consumption of van lifers

Let’s first look at our expected daily water consumption. We need to drink at least 2 litres of water a day in temperate climates to avoid dehydration. In hot climates and high humidity, we need a lot more. Then you might like an occasional shower. An average shower uses 35 litres of water. Even if you adopt the military approach (tap on – get wet, tap off – soap up, tap on – quick rinse – tap off) you’ll still use around 12 litres.

Include water for cooking, cleaning house and laundry and you could consume 50 litres a day. There are plenty of creative ways to conserve and reduce water consumption though. Based on our own experiences, we reckon frugal users will average around 25 litres per day, per couple.

Water top ups in a camper van

Now consider how often you can replenish your water supply. This depends on what sort of van life you’ll live and where you’re going. It’s easy to get free water in most camper stops around Europe so get away with carrying enough water for 2 or 3 days. In contrast, access to drinking water is more challenging in Africa. Even so, with few compromises and effort to conserve water, you can still avoid fitting huge tanks.

Find out how to sleep for free in your camper van in Europe

We’ve seen some overland trucks fitted with 1000 litre water tanks. Finding 1000 litres of drinking water is a challenge in some parts of the world. There aren’t many garden taps once out of Europe. Even if you find a hand pumped well in a remote African village, a responsible traveller won’t take so much. Besides, 1000 litres of water weighs 1 tonne and needs a cubic metre of load space. To us, these points alone outweigh any benefit.

In our Unimog camper Mowgli, we carried 230 litres of fresh water. We bought Mowgli pre-built so this wasn’t our design decision. Even so, we had plenty of water. The longest we lasted on one tank was 9 days, the last 2 of which we were ultra careful on our consumption. With the Sprinter van conversion, we’re going for a little less. We’ll fit Baloo with 160 litres of fresh water, including hot water. If we wanted to carry more water, we’d have to give up storage space. We’re not willing to compromise the floor layout we’ve chosen though.

We’ll post an article soon on the floor layout we’re planning for Baloo.

Planning the layout of the water system is key before starting the installation. There’s a lot to think about but by taking the time to plan it well, the installation becomes straight forward. Well, in theory at least.

The cold water system

Here’s the key considerations in designing the camper’s cold water system:

How to store cold water ready for use

The simplest solution is to store drinking water in a jerry can. It’s a proven and trustworthy solution to hold 20 litres of water in a robust container. Put it in a storage cupboard, strap it down to secure it and pour as required. It’s not the most elegant solution but it works.

Fixed water tanks offer a more robust solution for storing water in your camper van. Water tanks are available off the shelf for popular vehicles or made to measure if necessary. You can even have a few separate tanks joined by hoses if it helps with storage.

How to fill the water tanks

You need a way of filling the water tanks. Most camper vans and motorhomes have a filler fitting on the outside of the van leading to the water tanks. Some have a filler fitting just inside one of the doors, nearest the location of the water tanks. It’s really important that you have an air tight filler cap to avoid getting any air locks in your water system.

Water system layout in your camper van

There’s a few things to consider before finalising the layout of the water system. Where is the sink going to fit? Will you put it close to any bathroom you plan to install? The plumbing is easier to install if they’re close together. Where will your filler hose connect?

Will you store your water tanks inside the vehicle or outside? Outside storage of water in winter conditions may lead to freezing so you’ll need to think about this too. And make sure the chassis and cross member doest get in the way of the pipes in and out of the floor of the camper.

Does the layout allow easy access for future maintenance? You don’t want to dismantle the entire camper because you need to replace a pump now do you? And don’t forget to consider the weight distribution of full water tanks and how this might affect handling of the vehicle.

Take a look at this article for more info on modifying your overland vehicle.

Hot water in your camper van

Hot water in a camper van is a luxury and one we’re not happy to live without. We don’t have a huge capacity but it’s enough for washing dishes and an occasional shower. When designing your camper van water system you need to decide how you’re going to heat it. I’ve outlined 5 options here:


This is an efficient way of heating cold water through the engine’s cooling system. As you drive, water is circulated around the engine block, passed through the radiator and returned to the hot water tank. When you park up at the end of a long drive, you have tank full of hot water. Nice!

240v electric water heater

Less efficient than the coalescer, a 240v hook up is needed. Much like the old water tanks so many of us used to have in the attic at home, a heater coil is submerged in the tank to heat the water. The main advantage of this realised when you’re parked up on a campsite for a few days. With the available hook up, you’ll not run out of hot water for washing up. Bear in mind you’ll need an inverter to use the immersion heater too.

Click here for a full explanation of camper van electrics

12v immersion heater

A 12v immersion works in the same way as the 240v system, only no hook up is needed. Really you’d want to run your engine to heat your water though as otherwise it’ll drain your leisure batteries quickly. The downside of this method is you must remember to turn the heater off when you’re not driving. It’s perhaps the cheapest and most simple method of getting hot water in your van though.

Gas boiler

If you want to carry gas with you, you could go for a gas boiler to heat your water. It removes the dependancy on your batteries but I’d ask if the trade off is worth it.

Engine heated portable shower

This one is on our wish list and if we can save a few pound on Baloo’s budget, we’ll add one to our kit list! It’s similar to the coalescer except it’s more portable and fitted inside the engine bay. Dunk one end of the hose into a lake, well or river, run your engine, flick a switch and hey presto, hot water for as long as you like!

In our own camper van conversion, we’re fitting a coalescer and a 240v immersion heater. We have the ability to use a 12v heater too but there’s really no point because we’d never use our batteries to heat water.

Micro pore filter

In less developed parts of the world potable water, is not as clean as it might be elsewhere in the world. Our delicate stomachs might become upset, the water can have an off taste and at worst, it could harbour dangerous diseases. It’s fine for washing and even cooking if you boil the water, but you might want to avoid drinking it.

A micro pore filter is a simple solution to clean water and uses a combination of ceramic and carbon filters. The ceramic element removes most bacteria while the carbon elements eliminates most chemical traces. Whilst not 100% effective, they do improve water quality significantly. The relative low cost of the filter units make installation a bit of a no brainer if you plan to travel to any less developed countries.

If in doubt, boil your drinking water and add an occasional cap of bleach to your fresh water tanks to keep harmful bacteria at bay.

Read next: The essential guide to camper van ventilation and insulation

Camper van water systems design

Click through these slides for a simple explanation of a camper van water system set up.

Watch this space for our detailed camper van water installations guides coming soon.
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Camper van water systems explained - This post explains all you need to know about camper van water systems to help you design a set up fit for your chosen van life. Read the full article here: #SpinterConversion #VanLife #Sprinter4x4

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