Here’s our guide on how to build a DIY water system in a camper van conversion. Having running water and a hot shower draw the line between “van camping” and “home on wheels”, so let’s do this! It’s not that hard, we’re here to help 🙂 Here is how it goes:
- PART A (THEORY): we talk about water system in general; it’s the basic stuff.
- PART B (OUR SYSTEM): we talk about OUR water system.
- PART A: THEORY
- 1. Fresh Water Tank
- 2. Grey Water Tank
- 3- Black Water Tank
- 4- Water Pump
- 5- Accumulator
- 6- Sink
- 7- Hot Water
- 8- Misc (Pimp my System)
- 9- Plumbing
- 10- Winter
- 11- Hacks
- PART B: OUR SYSTEM
- 12- Identifying our Needs
- 13- Water System Diagram
- 14- Material List
- 15- Installation
- 16- Resources
This post contains affiliate links, which means that if you click a product link and buy anything from the merchant, we will receive a commission fee. The price you pay remains the same, affiliate link or not.
Alternatively, you can visit our Say Thanks! page.
PART A: THEORY
Before we go any further, remember that we’re not building a motor home here; we will focus on components and systems that we think are more appropriate for a camper van conversion rather than a RV.
1. Fresh Water Tank
1.1- What Size?
It totally depends on your usage and how many days autonomy (without having to fill) you want. As a rough guideline and to help you make your calculations, here is our usage living full-time in the van:
- One shower (one person) uses a little less than 3 gallons of water. (that’s being very careful not wasting water, i.e. turning shower off when soaping, etc.)
- We dump between 2-4 gallons of grey water from the sink every day. (we cook a lot, so we wash a lot of dishes; you might dump less than that)
That being said, we fill our 25 gallons tank (amzn.to/2Lk0vSj) every 4-5 days in summer (depending on showers). Every 7 days in winter (we shower in aquatic centers or such and drink much less water).
When choosing the size of your tank, remember that water is not a luxury it’s essential! Having to search for water frequently is no fun, so make sure to select a tank that gives you plenty of autonomy!
Water Tank Links:
1.2- Inside or Outside?
By installing our tank and plumbing inside the van, we can use our system even during skiing season, nice! It works in temperatures as low as -15F (-25C). Of course, having the tank inside occupies precious space in the garage but that’s a compromise we are happy to make.
If we were to use the van exclusively in summer, we might consider installing our tank outside the van, underfloor. Installing the tank underfloor frees garage space AND improves the van handling because it lowers the center of gravity.
If we were to start over, now that we know that we use much less water in winter, we would consider installing a tank inside AND a tank outside the van. The idea is to maximize water capacity without occupying too much space in the garage:
- In summer, we would use both tanks (extra capacity for showers)
- In winter, we would winterize the outside tank and use only the inside tank
- Remember, this extra precaution is because we use the van below freezing temperatures! If that’s not your case, there’s probably no point on doing this.
- That’s food for thoughts, we don’t have any installation layout/details for that…
1.3- Tank Anatomy
1.3.1- Fill Port
You guessed it, the fill port is used to to fill the tank. While motorhomes and most pro-built campervans have a port outside to fill the tank, we don’t because we don’t want the van to look like a RV; we like our van to look like a normal cargo van (people refer to that as being “stealth”).
The tanks we recommend (see “Water Tank Links” table above) have 1-1/4″ diameter fill hole (no threads). We plug it using this test plug (http://amzn.to/2nIEWj8):
1.3.2- Outlet Port
The outlet port is used to connect the water pump.
The tanks we recommend (see “Water Tank Links” table above) have 1/2″ NPT female outlet port (so a 1/2″ NPT male fitting is required).
1.3.3- Drain Port
The drain port is used to empty the tank for winterizing or for maintenance.
The tanks we recommend (see “Water Tank Links” table above) have 1/2″ NPT female drain port (so a 1/2″ NPT male fitting is required).
1.3.4- Vent Port
When pumping water out of the tank (or filling the tank), the water volume has to be replaced with air. That’s the role of the vent port. To prevent water coming out of the vent port (when breaking or on steep or rough roads, for example), a hose is connected to the vent port and we installed it about 15 inches higher than the tank.
The tanks we recommend (see “Water Tank Links” table above) have 1/2″ NPT female vent port (so a 1/2″ NPT male fitting is required).
See section 1.3.1 for picture.
2. Grey Water Tank
Grey water is what comes out of the sink drain (and shower, if we had one): water from washing dishes, washing our hands, brushing our teeth, etc. There are no excrement or chemicals in grey water.
2.1- What Size?
That depends on how often you don’t mind having to empty it. As a guideline, we empty our 4 gallons grey water tank almost everyday:
- Washing dishes is what uses the most water. We cook a lot, so we wash a lot of dishes! You might get less grey water than we do.
- If we use our hole-in-the-floor (see “Our System” section below), we don’t have to empty our grey water tank everyday…
2.2- Inside or Outside
Because we use the van for skiing in winter, we had to install our grey water tank inside the van so it doesn’t freeze. It uses some space under the sink, but we’re happy that we can use our sink during winter!
3- Black Water Tank
Black water is what comes out of a toilet; there are excrement and/or chemicals in black water. It must be emptied at a RV Dump Station:
3.1- Yay or Nay?
We don’t have a black water tank and we don’t need to go after RV Dump Stations. Neat! How is that? Because we installed a Nature’s Head composting toilet 🙂 And we’re SO GLAD we did! We talk about our composting toilet here (how it works, how it’s emptied, what frequency, etc):
4- Water Pump
Pump up the jam.
4.1- Diaphragm Pump
A diaphragm pump keeps the water system pressurized at all time. It’s like having running water, just like
at home a house.
4.1.1- How it works
The pump has no on/off switch. It starts automatically when the pressure drops and shut-off automatically when the appropriate pressure is reached. For example, using the sink (or shower or whatever) creates a pressure drop; the pump senses it and runs until the pressure goes up again.
Shurflo Revolution 4008 Specifications:
- Shut-Off Pressure: 55 PSI
- Re-Start Pressure: 40 PSI
- Recommended Fuse: 10 amps
- Flow: 3 Gallons Per Minute
4.1.2- Connecting the Pump
The Shurflo Revolution 4008 has one 1/2″ NPS male inlet and one 1/2″ NPS male outlet.
Because the pump produce quite a lot of vibration, it’s better to connect the pump using flexible pipes. We recommend using the Silencer Kit from Shurflo:
It’s also a good idea to install a strainer at the inlet port of the pump, so debris can’t find their way through the pump and damage it:
4.1.3- On / Off Switch
We just mentioned a diaphragm pump doesn’t have on/off switch, true. But adding one is a good idea. Indeed, if the water tank runs empty (which happens sometimes, you know…) the pump will run indefinitely and could be damaged. Also, if there was a leak somewhere in our system (which happened when we installed the Sea Tech push-to-connect fittings; we then got rid of them…), we could turn off the pump quickly and prevent a major mess.
We use the following switch for the water pump and for the cargo lights; we really like the design and the “feel” of it:
4.1.4- Electrical Wiring
The pump works on 12V DC and has a negative and positive wire. It doesn’t get easier than this! We wrote an in-depth article about campervan electrical system:
4.2- Manual Pump
To keep things really simple and to save on electricity, a manual pump can be installed:
If installing a diaphragm pump (like the Shurflo we recommend), you might consider adding an accumulator. The accumulator contributes to longer pump life, less noise, less amperage draw, and reduced water pulsation. And also reduces cycling (the pump starts less often), nice.
Per manufacturer: “The most efficient use of the accumulator occurs with the accumulator pressure set at the same pressure as the pump’s re-start setting.” (Hint: it’s 40 PSI for the Shurflo Revolution 4008 pump). We tested different pressures and we prefer to set it to 30 PSI as the water volume capacity is greater at that pressure (therefore the pump cycle less).
The pressure can be checked with a normal tire gauge (you have one in your glove compartment, right?) and adjusted with a bike pump (it’s a shrader valve), it’s super easy. When checking or adjusting pressure, just remember to turn off the pump and to open the sink faucet (this is to read the static pressure). The accumulator comes unpressurized.
6.1- For Pressurized System
Pretty much any sink will do. We recommend the Dometic VA7306AC sink because it’s compact, foldable and looks great. If your counter space is limited, it’s a great way to optimize it. Be aware that it’s a high-quality product with a high price tag. The only downside we found is that the foldable faucet is in the way when washing/rinsing large items (such as full size plate or casserole); we wish it was located further back so we don’t have to swing it around.
6.2- For Manual Pump
If going for a manual pump, keep things simple!
7- Hot Water
We don’t have a water heater (for the sink) and we’re totally OK with this: we just use our kettle to heat water. That’s the most economical way (water and gas) for sure! The most annoying part is that it’s not really practical to rinse the dishes using the kettle, so we rinse using cold water; that makes drying the dishes more difficult. For everything else, we don’t mind.
If budget is not an issue, you might consider the Webasto Dual Top Evo. It’s an air heater (similar to ours: faroutride.com/air-heater-installation) AND water heater combined. It works with diesel and has a 11 liters water tank integrated. Fun fact: it’s over $3K…
7.3.1- Tankless Water Heater (on-demand)
As the name implies, a tankless water heater has no tank. Water is heated on-demand, so it can provide a continuous flow of hot water. It’s super efficient since it doesn’t have to heat water all day.
Mr Heater BOSS
This is what we used for the first 10 months of our trip. It’s super safe, efficient, portable, but cannot be integrated to a pressurized system (it has its own pump). We really enjoyed using it and highly recommend it, but we finally installed an EccoTemp instead because:
- After 10 months we realized we don’t need our shower to be portable.
- We also realized finding water is fairly easy, so we don’t really need the extra 7 gallons Aqua-Tainer.
- Having to connect the propane and water each time is a little irritating.
Again, there’s nothing wrong with the Mr Heater BOSS if it answers your needs. Here is our full review:
After 10 months on the road, we finally replaced the Mr Heater for the EccoTemp (see justification above). It’s a popular option with a reason: it’s good, cheap and easy to setup. It can be integrated to a pressurized system (diaphragm pump, like ours) or it can be ordered with a standalone pump. Be aware that the manufacturer does not approve it for interior permanent installation. That’s why:
- We installed ours near the rear doors (so it’s fully vented).
- We installed a valve for propane AND water (so we can shut it off after each use).
- We drain it after each use (per manual).
Here is our review:
7.3.2- With Tank Water Heater
Atwood have a wide range of water heater models, but the one that catches our attention is the G8A-6E model. Overview:
- Tank Capacity: 6 gallons
- Water Temperature: 100F to 150F
- Energy: Propane
- Recovery: 11.6 gallons per hour
- Dimensions: 16″ high x 12.5″ wide x 18″ deep
Make sure to check Atwood website for all their available models: http://www.atwoodmobile.com/water-heaters.asp
8- Misc (Pimp my System)
8.1- Bike Wash (a.k.a Dog Poop Wash)
Washing a bike uses quite a lot of water, so we obviously don’t use it very frequently. But there are some occasions where the bike wash is a real life saver; removing a layer of mud from the down tube by hand is no fun!
Now, can someone explain why Antoine is CONSTANTLY walking in dog poo while Isabelle is not??! We’re thinking of renaming it for “Dog Poop Wash (a.k.a Bike Wash)” as it has become the primary use…
Let’s get straight to the point, PEX tubing is probably what you want.
- PEX tubing has become the standard for houses and RV.
- It’s cheap and readily available in any hardware or RV store.
- It comes in red/blue color to differentiate hot/cold side (both color as the same properties).
- It resists freezing (but fittings might crack, don’t let it freeze!) and high-temperature.
- It’s easy to cut, easy to connect, easy to route (flexibility: 5″ minimum radius for 1/2″ diameter PEX).
- It won’t corrode.
- Note that PEX is NOT UV resistant and should not be installed where is sees constant sun exposure.
PEX tubing can be cut with a carpenter knife, but a PEX cutter will make your life easier:
9.2- Leak Free Connection
This is the method we recommend for permanent, leak free connections. It’s easy, fast, fun (yep!) and there is very little chance for error. It’s also good to know that a clamp tool can clamp any ring size (as opposed to crimp). Here is how it goes:
- Insert the clamp ring on the outside of the PEX tubing.
- Insert the barbed fitting into the PEX tubing.
- Using the Clamp Tool, compress the clamp ring. The clamp tool will not release from the clamp ring unless a properly-secured connection has been made; therefore GO/NO-GO gauge is not required!
Crimping is very similar to Clamping; a crimp ring is used instead of a clamp ring. Both methods give as good results, except a GO/NO-GO gauge has to be used for crimping to ensure the crimp ring was sufficiently deformed. Crimping is the cheapest method for large projects.
9.2.3- Compression Fittings
The disadvantage with clamp/crimp is that it might be impossible to operate the tool in tight spaces. In that case we suggest Flair-it compression fittings as they require no tool for installation:
We personally haven’t tried them, but they’re very popular in the RV industry and they’re tried and tested. Flair-It fittings come in a variety of shapes and functions: amzn.to/2KqccKm
9.2.4- Push-to-Connect Fittings
Push-to-Connect fittings are almost too good to be true. Just push the PEX tubing into the fitting and voilà!
In fact, maybe they are indeed too good to be true. We first used these fittings to make our water system and when we applied pressure, 2 fittings disconnected and 2 had slow-leak.
- We’ll take the blame for the fittings that disconnected. We probably made the mistake of not pushing them enough. But we’re all human and we all make mistakes… in our opinion, a good design is a design that doesn’t allow to make mistake.
- Slow leak are the worst because they’re hard to notice and could create damage in the long run… Why had we a slow leak? The Sea Tech fittings rely on an O-ring that goes on the outside of the PEX tubing (not inside); the surface of the PEX tubing must be scratch and damage free. These fittings are “reusable”, but the action of disconnecting create scratches on the outside surface of the tubing…
- O-Ring dries and loose efficiency in the long run.
- Some people reported having no issue at all after many years, but we think they are too sensitive to installation, outside tubing surface condition and O-ring deterioration. We’re not 100% confident so we pass. (we would be OK with them for temporary repair or outside installation).
9.2.5- Threaded Fittings
For all threaded plastic fittings:
- Do not use Teflon tape or Teflon paste! These are lubricant, not sealant, and will promote over-tightening = cracks = leaks.
- Don’t over-tight: finger tighten plus one or two turns.
- Use plastic-safe thread sealant (not lubricant) such as LA-CO Plato-Joint. Don’t worry it’s not permanent; it’s a paste that does not dry and can be removed easily.
- We did not use thread sealant on the Shurflo fittings attached to Shurflo appliances (pump & accumulator).