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The Ultimate Guide to Campervan Water Systems

Updated: Oct 20

Hot water, cold water, showers, faucets, pumps, waste water, filtration, piping, and much more. This guide is your complete one-stop-shop for campervan plumbing. Learn everything you could ever want to know about campervan water systems, and more. In this guide I will walk you through several different campervan plumbing diagrams and look at how the campervan water pump system works. I hope this resource helps you build a beautiful campervan that you can be proud of for many years to come!


I'm Shane, I've been teaching people to convert campervans for many years, I'm the author of The Van Conversion Newsletter, the van conversion instructor at Udemy, and the proud owner of a beautiful self-build campervan called Beans. So let's jump in and see how to build an awesome campervan water system!

The ultimate guide to campervan water systems

Items linked in this guide are affiliate links. By using these links, you are helping me to continue writing free educational van conversion content!

You can find the full list of van conversion supplies here.


Index

 

Note: I thought I'd let you know that you can get a free electrical wiring diagram by signing up to The Van Conversion Newsletter 🙂

 

What is a campervan water system?

Simply put, a campervan water system pipes water from a storage container out to a tap or a shower. A simple water system may just have a foot pump and cold water going out to a tap, while a complex system will have an electrical pump feeding hot and cold water to a shower and sink. The complexity you wish to add is up to you!


In this article we will first look at the five types of campervan water systems at a high level. After that we will go deep on the different components that make up the water systems and how you can do the installation for yourself.


Now then, let's have a look at five campervan plumbing diagrams, increasing in complexity at each tier.


Five Campervan Plumbing Diagrams


1. Water Dispenser Bottle

Okay, not really a campervan plumbing diagram, but as simple as it gets... You can pick up a water dispenser bottle online very cheaply. Put water in the top, get water out the bottom 💦. No more need be said.

Water dispenser bottle

2. The foot pump: Cold water campervan water pump

The manual foot pump is a nice option that gives you cold water flowing out to a faucet. No electricity is required because the pump is operated manually with your foot! We have two large plastic portable containers, one for grey water and the other for fresh water. Here is a campervan plumbing diagram for the foot pump to help you get started 👇

Campervan water system: footpump

3. The Submersible Pump: Cold water campervan water pump

The submersible pump is a really great option that gives you cold water flowing out to a switched faucet. The 12v faucet is connected to a submersible pump, when the faucet lever is pulled, water flows! The submersible pump simply sits in a large plastic portable container full of fresh water. We will look at the wiring of the microswitch faucet later in this guide. Check out the campervan plumbing diagram for the submersible pump below.

Campervan water system: submersible pump

4. Heated Sink and Shower Water System

This is the god-tier campervan water system. This system gives you pressurised hot and cold water running out to a sink and shower. There are mounted fresh and grey water tanks; the fresh water tank is filled from an inlet in the side of the van and has an electrical water level gauge. The grey water from the sink can run either to our grey water tank, or outside the van. The cold water running to the sink tap is filtered, and we can get a mix of hot and cold water (to our liking) to our pressurised sink and shower.


Wow. How good does all that sound!! 😍


Though this campervan plumbing diagram can be a little complex to understand at first, it is incredibly rewarding/fun building this system; it feels like plugging Lego blocks together. We are going to go deep on the different components of this system throughout the guide. So strap in, and get ready for the ride! I guarantee by the end of this guide, you will be able to plumb your own campervan water system.

Campervan plumbing diagram - heated sink and shower

5. Hot water sink

If you don't want a shower in your van, but still want hot water faucets, the campervan plumbing diagram below will sort you right out! However beware! You will need at least a 3000W inverter if you want to use this type of faucet. Pretty cool though!

campervan plumbing diagram - hot water sink

What do I need for a campervan water system?

Now that we have seen the five campervan plumbing diagrams, let's explore some of the components of each diagram. We will explore the following essential concepts in depth:

  • Fresh water tank

  • Grey water tank

  • Water pump system

  • Sink and faucet

  • Water heater

  • Shower

  • Water piping

  • Pipe fittings

  • Water level gauge

  • Water filtration

  • Pipe insulation / heating

  • Water tank sanitisation and smell management

Let's go! 🍻


Fresh water tank

A fresh water tank holds... fresh water.


What size fresh water tank should I get?

Generally there are three sizes of fresh water tank: small (5L), medium (20L), and large (75L). I personally have four portable 20L fresh water containers in my campervan. If I were to do another conversion, I would install a large 75L fixed fresh water container instead and add a fill point in the side of the van.

Find out how to install a water inlet in your van.


Where should I put the fresh water tank in a campervan?

You have two options for where to put your fresh water tank:

  1. Inside the van

  2. Underslung to the bottom of the van

Having a fresh water tank underslung to the bottom of the van is a little more complex to install, but a really nice option that gives you more space inside the van. However, if you are are a winter vanlifer (like me) an underslung water tank is probably not the best idea as you are pretty snookered if it drops below freezing outside!


Winter vanlifers should keep all parts of the water system inside the van. Installing your fresh water tank inside the van is a safer bet and an easier install.


For small/medium water tanks (like mine), you can simply house them directly under the sink, for larger water tanks, you will probably house them at the back of the van (out of the way).


Next, let's look at how to mount a large water tank under a van - feel free to skip this next section if you are not planning on installing a large tank.


Anatomy of a large water tank

A large fixed water tank should have four water outlets:

  1. A Large filling inlet, where we fill the tank with water. This is normally piped to the water filling inlet installed in the side of the van.

  2. A smaller outlet running to the appliances (shower/tap)

  3. A vent outlet (the water that runs out of the tank needs to be replaced by air). If you have a filling inlet in your van, this often comes with a vent installed which means you don't have to install an inlet.

  4. And sometimes a drainage outlet which is used when you want to drain the water tank for cleaning.


NOTE: A water tank filling inlet and outlet drain operate by gravity. Ensure your filling inlet is mounted higher than the water tank, and ensure your drain outlet is mounted lower than the tank.


A large water tank may also have metal water-level probes pre-installed. These metal bolts (with spade connectors on the end) are there for if you want to install a water level sensor in your van. We will look at how to install a water level sensor later in this guide.

how to install inlets on water tank


How to manually install inlets in a water tank

Sometimes you will end up with a blank water tank that has no outlets pre-built. In this case, you will need to install them yourself. This can actually be a good thing as it means you get to choose the diameter of the outlet, rather than relying on the supplier.


If your water tank does not have outlets, you can easily install them by first cutting out an appropriate sized hole in the plastic container with a holesaw. The holesaw you use should match the OD (outside diameter) of the outlet fitting you will be using. eg. if the OD of the fitting is 1", use a 1" holesaw!

Hole saw water tank

Next install an appropriate outlet fitting. Here are the typical sizes we use for the inlets for our fresh water and grey tanks


Fresh water tank:

Grey water tank:

Water tank connector fittings
Water tank connector fittings

The connector comes with a backing flange that normally goes inside the container and into which we screw. However if you have no access to the inside of the water container (because there is no access hatch installed), worry not! Without using the backing flange, you can still screw the fitting into the cavity you cut in the container; if you have used the appropriate hole saw size, you should have a perfect seal. Make sure the rubber O-ring is placed between the connector fitting and the water container to get a nice seal.


If the cavity in the water container is a little small, you can heat the plastic a little (using a small blow torch) and then tighten the fitting in place (a pipe wrench is best to tighten fully). If you heat the plastic first, you are actually doing some minor plastic welding which can improve the seal. After the fitting is in place, I would recommend adding sealant around it to ensure a watertight joint.

Heating the plastic container before screwing the fitting
Heating the plastic container before screwing the fitting

How to install an underslung water tank

Broadly speaking, there are two ways to underslung a water tank to a campervan:


Option 1: Mounting brackets and hook bolts

This is the most sturdy way to install an underslung water tank, however you need to make sure the mounting brackets are perfectly sized for the water tank you have; this can be a challenge if purchased separately.

Water tank mounting brackets
Heating the plastic container before screwing the fitting

To install the mounting brackets, we will need to drill some holes on the underside of the van (be bloody careful where you drill!). The hook end is placed into the drilled hole and simply hangs there. The water tank is then placed against the underside of the van, and the brackets are secured (thus holding the tank) onto the hook bolts using the nuts provided.


Option 2: Hanger straps

Hangar straps will likely be a little less sturdy, but are guaranteed to work no matter what size water tank you have.

Water tank mounting brackets

How to mount a fresh water tank inside your van

Some people choose to keep their fresh water tanks inside the campervan, either for ease of installation, or because of freezing conditions in winter. If you choose to mount your water tank inside, make sure you secure it tightly to vehicle so it doesn't move when driving. You can use cargo lashing straps to keep it in place (these can also be used for to secure your gas bottle).


Grey water tank

A grey water tank holds all the dirty water that pours down the drain from you sink and/or shower. It is important to note that this is not the same as a black water tank (which holds the waste from your toilet). We will not be discussing black water tanks in this guide.


The grey water tank is usually. little smaller than your fresh water tank, the sizings are are generally the following:

  • Small grey water tank: 5L

  • Medium grey water tank: 10L

  • Large grey water tank: 45L

The specifications and mountings for a grey water tank is much the same as a fresh water tank. The main difference is that a grey water tank may have an access hatch to allow you to get your arm in there and give it a good clean. If it doesn't have one, you can use a hole saw to cut an appropriately-sized circle in the container, add a bead of sealant around the new hole, and then simply pop the access hatch into the cavity. If the fit does not feel solid, you can also screw the access hatch into the container (add a bead of sealant over the screw head when you're done).

Water tank access hatch

Air vent

The filling inlet point contains the air vent required for the fresh water tank. Here is a guide on how to install a water filling inlet.


However, we will need to install an air vent manually on our grey water tank. This is a simple installation. Just like the other inlets and outlets of the water tanks, we will need to install a 1.5" water tank connector fitting first. We then screw an air vent into that connector fitting. We are going to discussing how to use connector fittings later in this guide.


Drain

We also need to install a drain on our grey water tank. For this we will connect some 1" PEX pipe to the grey water tank with a 1" barb-pipe fitting. This PEX pipe runs outside our van to a spigot. We can secure / mount he spigot to the underside of the van using 1" P-clips. We will discuss PEX piping at length later in this guide.

1" water tank spigot

Campervan water pump system

Let's examine the three types of pumps for the campervan plumbing diagrams shown at the start of this guide: manual pumps, submersible pumps, and diaphragm pumps.


Manual campervan water pumps

There are three types of manual campervan water pumps, all of them are very straightforward to plumb. The three types of manual pumps are:

  1. Baby foot pump

  2. Gusher pump

  3. Faucet pump


Baby foot pumps

The baby foot pump is the cheapest campervan water pump. It is not very powerful in terms of how much water it delivers, but it is very small! The baby foot pump has a 1/2" barbed inlet and outlet, onto which we attach 1/2" PEX tubing. The inlet side runs to our water container, the outlet side runs up to our cold only faucet. We attach the PEX pipe to the faucet with a 1/2" barb-pipe connector fitting. As I mentioned before, we will be discussing connector fittings and how to use them at length later, so don't worry about the 'how' for now.

Campervan water pump - baby foot pump

Gusher foot pumps

The gusher pump is plumbed in the exact same manner as the baby foot pump. However it is a far superior pump, normally delivering 4 gallons of water per minute!

Campervan water pump - gusher pump

Faucet pumps

The faucet pump is really handy! It combines a manual pump and faucet into one! And the plumbing is even easier than the other two options. We simply run 1/2" PEX tubing from the water container up to the faucet. That's it.

Campervan water pump - faucet pump

Submersible campervan water pumps

This is the style of water pump I have in my campervan. I really like it - cheap, cheerful, and it does the job. The submersible water pump is connected with 1/2" PEX tubing to the faucet, it is also wired up to the microswitch tap in the faucet. We need a special 12v electric tap (microswitch tap) in order to use a submersible campervan water pump. Shurflo's electric faucet is commonly used, however I personally think this one looks a bit nicer.


Submersible campervan water pump wiring diagram

I want to quickly look at the wiring diagram for an electric tap and submersible pump as this information is not easily found online! (I know from experience...)


To wire a submersible pump to a 12v electric tap all we need is a strip connector with three parts. Here is the wiring diagram:

Campervan water pump wiring diagram

If you haven't read this guide on connecting wires, go check it out. It explains how to use strip connector blocks and ferrules (the wire connector needed for the installation).


Diaphragm pumps

The diaphragm pump is used in a campervan water system with a heated sink and shower (the fourth campervan plumbing diagram). Let's zoom in on the campervan water pump part of the diagram. The component marked 'shurflo pump' is the diaphragm pump.

Campervan plumbing diagram for the campervan water pump

Let's learn about the diaphragm pump as well as the components surrounding it. There are four key components:

  1. Pump silencer

  2. Water strainer

  3. Diaphragm pump

  4. Accumulator.

Note: I would recommend buying the brand Shurflo for all of the above four items. If you only buy Shurflo, you can be sure that the appliances will connect together very easily.


Pump silencer

A pump silencer is designed to reduce noise and vibration in plumbing systems. Diaphragm pumps can be quite loud - these devices help! They are simple hoses that reduce the rattle.

Campervan water pump silencer

You should buy two pump silencers (they normally come in a pack of two anyway). The first silencer goes on the water tank side of the pump, the other goes on the sink/shower side of the pump.


The first pump silencer screws directly into the water strainer, the second pump silencer screws out of the accumulator. The pump silencer has 1/2" fittings, in keeping with all Shurflo appliances. We will talk about both the pump silencer and accumulator next.


Water strainer

A water strainer keeps your pump clean, clear, and eliminate unnecessary repairs by keeping debris and other particles out of the pump. The bottom of the strainer is transparent so you. can see when you need to clean it. It simple screws directly onto the diaphragm pump.

Campervan water pump strainer

Note: Arrange all strainers and filters iverticalicle position! This is for 2 reason. First, when you service them they will be full of water and WILL SPILL their entire contents out when you unscrew them. Secondly, mounting them horizontally and not supporting the bottom end puts tension on the threaded connection. When they are filled with water they are considerably heavier and overtime WILL BREAK that plastic thread with the abuse of being in a bouncy van.


Diaphragm pump

A diaphragm pump operates like the diaphragm in the human body; when the diaphragm expands, air enters the lungs / water enters the pump. When the diaphragm contracts, air leaves the lungs / water is pumped out to appliances. A diaphragm pump keeps the water system pressurized at all times. It is just like having running water in a house.

Campervan water pump - diaphragm pump diagram

The diaphragm pump is a 12v electric appliance, accordingly, it need to be connected to power from our 12v leisure batteries. A diaphragm pump has no ON/OFF switch built in. It starts automatically when the pressure drops, and it shuts-off automatically when the appropriate pressure is reached. However, you should probably run the pump to a switch so that it can be turned OFF when you're not using your campervan or to prevent the pump from running indefinitely when the fresh water tank is empty. Here is a guide on how to wire up a campervan switch panel.


The self-primed Shurflo diaphragm pump pumps 3 gallons per minute at 45 PSI. It has a built-in check valve to prevent back-flow and is relatively low-noise when compared to other makes.


Accumulator

An accumulator is a mechanical device that smooths out the flow of water from a diaphragm pump. Because a diaphragm pump pumps like lungs or a heart, it causes water to eject in spurts. The accumulator fixes this issue. It has the added benefit of increasing the lifespan of your pump, saving battery power, and reducing the noise of the pump.

Campervan water pump accumulator

The accumulator is attached to the diaphragm pump using a Shurflo pipe-barb wingnut connector on each appliance (with a short length of 1/2" PEX pipe connecting the two).

Campervan water pump connector fitting


How to pressurize an accumulator

The accumulator comes depressurized, so you will need to pressurize it. First connect up the accumulator to the system; leave all faucets and valves in the campervan water system open. Next, you will need to pump up the accumulator, just like you would a football! Pressurize the accumulator to 30 psi. An all purpose air compressors will do the job perfectly.


Barbed valves

As you may have seen from the campervan plumbing diagram at the beginning, there is a barbed valve (1/2") on either side of the diaphragm pump system. This allows us to isolate and empty the campervan water pump in order to clean it or repair it if needs be.

Campervan water pump barbed valves
Barbed valves

Sink and faucet

Let's explore sinks and faucets.


Types of sink

The sink one chooses for their campervan is more a matter of interior design (and budget) rather than functionality.


Here are some of the most popular sinks for campervans:


Basic sink

Does what it says on the tin.

Campervan basic sink

Sink with built-in chopping board and strainer

If you can afford it, this option is prettttyyyy great. Space in a campervan is EVERYTHING. The fact that this sink frees up space by doubling as a chopping space and drying rack appeals to me a lot.

Campervan sink


Classic campervan sink with built-in faucet

This is the most common sink you will find in campervans around the globe. It has a lid which folds down (giving you more room in the kitchen). It also has a built-in hot/cold faucet (you can get a cold-only version too). The faucet is electrical, thus wired in the same we saw for the submersible pump. However if you are using this with the hot/cold sink & shower campervan water system (aka a pressurized water system), you don't need to wire up the tap switch.

Campervan sink with faucet

Sink drain

Needless to say, the drain is a vital part of any sink. The drain in a campervan water system runs to out to the grey water tank (or outside the campervan if we are installing a more sophisticated system).


To install a sink drain we need two components:

The basket strainer is placed inside the sink (from above) and the drain pipe is screwed into the basket strainer from below. Plumber's tape should be used for this connection (discussed later).

Campervan sink drain hose

For a simple campervan water system setup, this alone will do; we can simply run that drain pipe down to a portable grey water container under our sink. However if we are doing a more complex setup with a fixed grey water tank and exterior drain we will need a couple more components.

Campervan plumbing diagram - grey water system

How to build a split drain in a campervan

To build a split drain, we run our 3/4" campervan drain pipe down to a 3/4" Y-valve. With the twist of a knob, this Y-valve allows us to choose whether we want the dirty water to run into our grey water tank or directly out of our van (if we are in a location where it is okay to do so!).


Exterior outlet

On the exterior outlet side of the Y-valve, we can simply connect up a garden hose and run it outside the campervan. You will use a holesaw to cut an appropriately sized hole in the bottom of your van (ensure the location you choose is safe!). You can secure the hose in place to the underside of your van with 3/4" P-clips.


Grey water tank outlet

Using a 3/4" GHT-barb fitting (GHT means 'garden hose thread') we can run some 3/4" PEX tubing to our grey water tank, it connects to the tank with a 3/4" barb-pipe connector and a 3/4" tank connector.


I know there is a lot of lingo here about tubing and fittings - don't worry! I will explain what all this means very soon :)


NOTE: You might have noticed from the campervan plumbing diagram (or from the linked products) that when we are connecting two fittings together (eg. the Y-valve to the GHT-barb fitting), it is very important that the fittings are made of the same material. Metal to metal, or plastic to plastic. Never connect plastic and metal fittings together or you risk threading the plastic fitting and creating a leaky connection.


Electric valves for grey water tanks

Okay, so electric drain valves are entirely optional (and not included in the standard campervan plumbing diagram supplied in this guide). However if you are building out the ultimate-mega-cool-all-in campervan... why not? With the flick of a switch you can drain your grey water tank (make sure your van is perched somewhere that is okay to drain!).


The installation of an electric valve is actually quite simple; on one side we screw in the 3/4" drain pipe coming from our sink, we screw the otherside into the top of our 3/4" Y-valve.

Grey water electric ball valve

Types of faucet

For the sake of a van conversion, there are three types of faucets we can consider:

  • Pump faucet

  • Microswitch faucet

  • Heater faucet

  • Regular faucet

Pump faucet:

We saw the pump faucet before, it allows us to manually pump water from the faucet itself.

Campervan water pump faucet

Microswitch faucet:

We also saw the microswitch faucet before. This faucet is required if we are using a submersible pump. Electric microswitch faucets are generally cold-only.

Campervan microswitch tap

Both a pump and microswitch faucet are quite simple to install. We run a length of 1/2" PEX pipe to the cold-only faucet directly from our fresh water tank. The microswitch pump is wired up to our batteries per the wiring diagram we saw previously.


Heater faucet:

The heater faucet is really cool. You plug it into an AC plug socket (inverter) and you get immediate hot water straight from the tap! 😮 It heats the water in <3 seconds and even tells you the temperature of the water. Really, really Unreal.


NOTE 1: You need at least a 3000W inverter to use this type of faucet as the device is rated at 2500W.


NOTE 2: You could get away with using a submersible pump with this type of faucet (rather than the diaphragm system), however you would need to install a switch manually as the heater faucet does not have microswitch to the best of my knowledge. In other words you would have two gadgets to operate the faucet: the manual switch to operate the pump, and the faucet lever to control the temperature and allow flow.


Here is a guide on how to install an inverter if you are interested in setting one of these bad boys up!

Campervan hot water faucet

A heated faucet also only has a single cold water pipe running to it. However, A faucet connector (compression fitting) is used to connect the water source to the faucet in this case. We then connect a 1/2" PEX pipe to the faucet connector using a metal barb-pipe fitting.

Faucet connector
Faucet connector


Regular faucet:

The last type of faucet is the regular faucet. There is no electric microswitch in these, they need pressurised water running to them to function. Because of that, they will only work with the diaphragm pump system. You can get a cold-only faucet or a hot/cold faucet (I really love the design of this one).

Campervan hot cold faucet

A regular faucet is much the same installation as a heated faucet except with two water inlets: a hot and a cold. Both the hot and the cold PEX piping are connected to the faucet using faucet connectors.


Water heaters

You have three options for supplying hot water to your campervan water system:

  1. Heater faucet

  2. Tankless water heater

  3. Water heater with a tank

No hot water

Before we hop in an examine the three types of water heaters, I think it is worth pointing out that not having hot hot water is always an option. You can always boil a kettle to wash the dishes, and many people choose to use campsites, gyms or coworks for showering.


Heater faucet

We discussed the heater faucet before so I won't spend time on it here.

Instant hot water from the faucet, using 2500W of electricity. That's all you need to know.


Tankless water heater

Tankless water heater heaters (nearly) instantaneously deliver hot water whenever you turn on the tap or shower. There is no holding tank for water and thus they take up less space than their 'with-tank' counterparts (discussed next). Tankless water heaters predominantly run on propane gas.