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Camper Van Plumbing: A DIY Guide

So you’re starting to think about the camper van plumbing stage of your build? Well hopefully we can help by sharing what is included in ours, why and how we put it all together.

Camper Van Plumbing

We are super happy with our van life water system and so pleased we opted to invest in a hot water heater. As we have a shower too, it makes for very comfortable living.

We happen to have a LWB Mercedes Sprinter. But the camper van water system we installed is completely versatile and thus universal for any make of van conversion.

Camper Van Plumbing

Disclaimer: We’re not professional plumbers. All the skills we employed in converting our van are completely self taught. So, basically, if you follow what we did and something goes wrong, like you err… flood your van. That’s on you. Just saying!

Camper Water System Diagram

Here’s our camper plumbing diagram to give you an overview of how our water system is connected. We’ll get into the nitty gritty below!

Camper Water Tanks

So there’s a few important things you’re going to have to decide early on when it comes to your van conversion water system.

First up is how much water capacity you need. And the best way to work this out is to do a rough calculation of how much water you think you’ll be using per day in the van. Break it down for cooking, drinking, washing the pots and washing yourself.

Then multiply that by how many days you’d realistically want to go in between fill ups to get your fresh water tank capacity.

As a comparison we (2 adults living full time in our van) use between 15-20L of water per day. So our 100L fresh water tank lasts us 5-7 days.

Camper Water Tanks

Of course it’s impossible to work out exactly, but you should try to calculate a rough estimate for your circumstances.

Then based on that you need to look at where the size tanks you need will actually fit on your vehicle. And whether you want them to be underslung or not.

And lastly, are you going to have hot water? Because as nice as it is, if you aren’t including a van shower and just using your van conversion for the odd getaway, it might not be worth the expense or effort.

We live in ours full time so for us it makes complete sense to have the luxury of hot water.

Campervan Fresh Water Tank

Okay, so you’ve worked out a guesstimate of how much fresh water you’ll be needing to accompany you on your adventures. And you’ve looked at options for where you can physically put it within your camper van plumbing system.

We have our 100L fresh camper water tank inside. There were a couple of factors behind this decision. Firstly, in order for it to be underslung and have room for the other underslung amenities, we would have had to move our spare wheel onto the back doors.

An extra job and expense we didn’t want. Especially being as we have a fixed bed so had plenty of space in the garage for it.

The other reason is that we knew we were going to be living in the van over a UK winter. Which was going to be uncomfortable enough without being able to make a brew first thing because the water is frozen.

campervan fresh water tank

The dimensions of the 100L camper water tank we have are 1016 x 445 x 241 mm. It slots neatly between the wheel arch box and our under bed cupboard. We built a base for it to sit in which is bracketed to the floor. With the tank ratchet strapped to that, so it can’t move at all.

Camper Van Waste Water Tank

It’s a little more difficult to work out what size grey water tank for your camper van plumbing will be best.

But most people tend to half the capacity of their fresh water tank. We have a 52L one. It works well for us as our campervan water tanks usually need emptying and filling around the same time.

But because we use a non-toxic, plant based washing up liquid we do give ourselves a little extra capacity by emptying our washing up bowl outside when it is appropriate to do so.

We bought our 52L Sprinter grey water tank as a kit which came with the underslung fixings. We opted to put it outside. Because it’s both more convenient to empty that way and we wanted to put it as close to our shower and sink as possible.

Camper Waste Tank Kit

So it sits directly underneath our shower and sink, up in the sill cavity behind the driver’s seat. We had to drill a couple more holes in the cross beams of the chassis for the brackets, but it was still straightforward to do.

The company we got it from does lots of these kits for specific van makes and models. So if you’re in the UK, it’s highly likely they’ll have a kit for your van conversion.

Van build tip: Put some extra nyloc nuts on your bolts to prevent those bad boys shaking loose.

Watch us installing our campervan water tanks:

Van Conversion Water Heater

We’ll just briefly mention our sprinter van water heater here, because again it’s universal and we go over it all in more detail in a dedicated review post.

But just to give you a few helpful details here, it’s a Truma Ultrastore 10L Water Heater. Which means that it heats up 10L of water and stores it in it’s own inbuilt tank. It takes around 20-30 minutes to get to 50/70°C respectively and will generally stay hot for around 2-3 hours.

best water heater for van conversion

It either connects to gas or 230V electricity, or both if you want the option to switch between. We just have it connected to our LPG system.

The Truma water heater comes with complete installation/operating instructions. Plus the fixtures and fittings you’ll need. Including a template for cutting the hole through the side of the van that you’ll need for venting it.

Although it initially looked quite complicated and there were a few trickier parts, it was on the whole relatively straightforward to install.

Watch us installing our camper hot water heater here:

Campervan Water Pump

After reading a few reviews, the water pump we decided to use was the Shurflo Trail King 30PSI 7L/min. Joined to that we have a Shurflo accumulator and a Shurflo water filter.

camper van water systems

The accumulator is a device that acts as a small water reserve so that when there’s small pressure drops in your camper van plumbing system, the water pump isn’t being triggered all the time.

And the filter just makes sure that any corrosives don’t find their way into your water pump. Especially important when you’re filling up from unknown water sources.

It was simple to install. The parts just screw together. Then all you need to do is extend the water pump cables through a switch and fix it in place. And voila, just connect your water supply to it.

Camper Waste Plumbing

Because our campervan waste water tank sits directly underneath our sink and shower, the waste pipes from each simply come through the van flooring and into each respective side of the tank. Then on the side where the sink waste goes in, there’s the outlet tap to empty it.

It seems very simple, but boy did this take some working out. You see the tank just comes with the pipe for the outlet valve and then two 25mm inlet pipes. Which is not only tiny, but also just a really odd size. Bearing in mind also our sink came with a standard 40mm waste setup.

Camper Waste Plumbing

So what we ended up doing was using a couple of reducers. Inside the van, after the trap, we have a connector that takes the waste pipe down from 40mm to 32mm. Then underneath the van another connector, just before the tank, that takes it from 32mm to 20mm.

campervan waste water tank

Our shower was a little simpler because we just used 32mm waste fittings all the way.

So the drain is 32mm, that feeds straight through the van floor and connects to a piece of flexi pipe that also doubles as a trap. Then we just cut a 32mm hole straight into the tank, around the second 25mm inlet, and fixed the shower waste straight into that. Bingo.

under van water tank
camper shower waste water system

Fresh Water Pipework

The fill pipe we have for our fresh water tank is just a standard 40mm piece of corrugated flexi pipe. That connects our fresh water tank to a fill point we have mounted in our garage area and is held in place by a couple of jubilee clips.

A length of clear PVC tube also connects between the fresh water tank and the fill point to allow the air out as you are filling. That’s just shoved on.

Fresh Water Fill Point External

Coming out the bottom of our campervan fresh water tank is the outlet pipe and drain valve. We ordered these from the same place we got the tanks. But they are essentially just a short thick piece of hose and a simple open/close valve.

Fresh Water Drain Valve

We did have some issues with this when we filled up with water. In that we had only sealed it with jubilee clips but the pressure was causing a really slow drip coming from the seal. So we took it apart and stuck it back together with silicon and it’s been fine ever since.

The standard outlet pipe that it came was a bit of a pain as it’s 15mm. But we just used a JG push fit 15mm-12mm reducer to take it down a size to fit with the rest of our pipework.

Campervan Water Pump

Off that a 12mm cold water pipe first runs through an isolator valve and then onto the filter, water pump and accumulator. We then have another isolator valve so we can completely isolate this section of our campervan plumbing.

Van Conversion Plumbing

A tee splitter then separates the water flow into two separate lines to create the cold and hot flow for our camper van plumbing system. The cold water pipes run straight up into the living area of the van, feeding the sink tap first before another tee splitter joins it to the shower tap.

Before the other water pipe goes into the Truma water heater, it first has a non-return valve and a drain valve.The non return valve stops any water being pulled out of the water heater the wrong way by the sink or shower taps.

Cold Water Pipe Work

The drain valve came with the water heater and is simply so we can drain it if needed.

From the van conversion water heater, the 12mm hot water pipe runs into the living area alongside the cold water pipe. It too is split to feed the sink and shower tap. Both are fixed in place onto either the van wall or floor with 12mm pipe clips.

We also used 12mm JG push fit pipe inserts. These go in the end of any section of hot water pipe. So both where you have your push fit joints and where it connects to your taps. We used as few joints as possible so that there are less places for leaks.

Van Conversion Shower Pipes

For our particular sink tap we needed some male JG tap connectors to fit the water pipes onto the sink fittings. And for our shower tap we needed to put female JG tap connectors to fix the water pipes onto the shower plate.

The shower plate then connects to the actual shower tap with brass S connectors that came included with the shower fixtures and fittings. We used PTFE tape on these joints. As we did on the non JG fittings that came included with the sink tap.

Water Tank Fill Gauges

Attached to both of our camper water tanks – waste and fresh – are electric fill gauges. We had the connections on the tanks fitted by the seller. So all we had to do when they arrived was run the cables to the gauge and connect that up with a power supply.

Water Tank Fill Gauge Monitor

They work by the water level inside the tank completing the electric circuit. The waste water tank fill gauge is just a full indicator. But the fresh water gauge shows whether that tank is full, half, quarter or empty.

Van Conversion Sink

When our sink first arrived, we were like, woah – And we very nearly sent it back. But actually because of the position we have it in, along with the sink tidy and washing up bowl in, it’s pretty damn perfect.

van conversion sink
sink for van conversion

Our tap is a mixer style one with an extendable head and a couple of different flow options on it. It’s lush and super handy for washing clothes or your hair. Again, it’s pretty large, but a piddly little tap would have looked a bit crackers with the sink.

Both came with all the fixtures and fittings we needed to install them. It was just a case of screwing things together and waterproofing and sealing with a good quality flexible silicon.

Van Shower

We have a whole step by step blog post on how we built and waterproofed our custom shower room so we won’t get into that here, you can read that at your leisure.

van shower
van plumbing shower head

Van Conversion Toilet

Our toilet isn’t at all fancy, it’s just a bog standard camper toilet. Bog standard – get it? Ah, never mind! Anyway, it’s a Thetford Porta Potti 365 and it has a 21L black tank.

It’s completely separate to the rest of our camper van plumbing system – in that it’s not physically connected to it. But we keep it in our shower room, removing it when we shower.

van conversion toilet

I just thought I should mention it here in case you were thinking we didn’t have one!

I mean that fact that we installed a shower and have hot water should give you an indication that we are unlikely going to be heading off into the woods with a shovel for a wild poo on a frosty morning.

We are currently using an eco friendly top and bottom tank toilet fluid that is 100% free from nasty chemicals and safe for the environment. It works a treat and is worth checking out.

Camper Van Plumbing Kit

Okay, here’s all the components we used in our campervan water system – without the waffle. Obviously depending on where you are reading from they may differ slightly in your country. But where possible we’ve put product links.

P.S. These are affiliate links, so if you buy through them we may earn a small commission from the sellar. It’s at no extra cost to you so is a lovely way to say thanks for the free info we’re providing here.

Water Tanks & Connections

Shower & Sink

Water Heater & Pumps

Pipework & Connectors

Without boring your tits off over the matter, we’ve tried to go into as much detail about our camper van plumbing as we can. But hit us up in the comments if you think there’s anything else we can help you with.

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Sunday 11th of June 2023

Your blogs are always so helpful, thank you! I'm just wondering about the tap.. do standard taps need any special adaptors to turn the pump on or does it just work? Thank you !

Sarah McAlister

Monday 24th of July 2023

Hey Sara, thanks so much. No there's no special adaptors - the pump just works off pressure so when the tap opens it automatically turns on :-)

Adam S

Monday 22nd of May 2023

Hey guys!

Thank you for the amazing info!

Have you guys had any issues/leaks with the push fit connectors? been reading that the "o" rings can be temperamental and leak pressure.

I was also wondering, after you fitted pipes through the floor what did you guys use to protect the pipe from sharp edges and sealant did you find worked best?

Thank you so much for the guide, our CAK tanks have been a bit of a mare so super helpful :)

Sarah McAlister

Monday 24th of July 2023

Hey Adam, yeah those CAK tanks - I don't know why the fixtures have to be so annoying! We did have just an initial issue when we first installed them & hadn't pushed them on tight enough but since then we haven't had any leak or pressure issues no. And we've driven some miles and some bumpy roads too! With regards to the pipe through the floor, we just filed the metal smooth, treated the bare metal with hammerite and then ran a bead of sikaflex around to seal it.


Sunday 26th of March 2023

Hi! Your videos and posts have been so helpful to me with my build. I’ve bought the same shower as you and was just wondering if the water pump automatically turns on when you turn on the shower, or do you have to turn the pump on separately?


Sarah McAlister

Sunday 23rd of July 2023

Hey Kira, that's so lovely to hear, thanks! So we have our water pump on a switch, but it's always turned on so yeah it just comes on automatically when either the tap or shower is turned on. The only time we turn it off is if we are running low on water so that it doesn't get damaged :-)


Monday 16th of August 2021


Good job !

Just wondering, the waste water hose (Grey), did it come with those PVC ends on each side or you fit them yourselves? (I can't find any link/info about it on the article.)


Sarah McAlister

Saturday 26th of March 2022

Thanks Amine. The grey waste water pipework (and trap) came with the sink. It's a standard 40mm.