Here is our guide on how to build a DIY water system in a camper van conversion. Having running water and a hot shower draws the line between “van camping” and “van life”, so it’s well worth the efforts. Designing a van’s water system is much simpler than the electrical system. A few items will do the trick: a water pump, fresh & grey water tanks, a sink, and some plumbing hardware. Let’s build stuff!
Table Of Content
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1- Campervan Water System In A Nutshell
The role of the water pump is to create and maintain the pressure in the system at all times. As a result, opening one (or multiple) faucet(s) will produce water immediately. But taking water out of the system lowers the pressure… that’s OK because the water pump is pressure-activated; there is no ON/OFF switch. When the pressure drops because a faucet is opened, the pump senses it and starts pumping to bring back the pressure, and it will continue pumping until the full pressure is restored.
The accumulator creates a pressure buffer. A larger volume of water has to be taken out of the system in order to lower the pressure. As a result, the water pump starts less often and the pressure is more constant. Note that the accumulator is optional.
The grey water tank collects water from the sink. We opted for a relatively small, portable grey water tank (there’s a handle on it) that is connected to the system via a quick-disconnect; so it’s very easy to dump it. Note that we also have the option to dump grey water through the floor, depending on where we’re parked.
We do not need a black water tank because we have a composting toilet. At last, we added a propane instant hot shower and a bike wash to the system. The final result looks like this:
1.1- Water System Diagram
1.2- Items List
|Fresh Water Tank||25 Gallons||1||Amazon|
|Test Plug||To plug the fill hole of the water tank||1||Amazon|
|Water Tank Filler with valve||To fill the water tank||1||Amazon|
|Fitting: 1/2″ MPT to 3/8″ Barb||To install the vent hose||1||Amazon|
|Hose: 3/8″ I.D. clear||That’s the vent hose||1||Amazon|
|Fitting: 1/2″ MPT to 1/2″ PEX||To install the drain valve||1||Amazon|
|Valve: 1/2″ PEX||To drain the fresh water tank||1||Amazon|
|Fitting: Shurflo 1/2″ MPT to 1/2″ Hose Barb||To install the vinyl tubing for the drain||1||Amazon|
|Tubing: 1/2″ Braided Vinyl Clear||Flexible drain that can be folded away||1||Amazon|
|Shurflo Water Pump||Diaphragm Pump, 3 gallons per minute, 55 PSI||1||Amazon|
|Shurflo Accumulator||To reduce cycling||1||Amazon|
|Shurflo Strainer||Prevent damaging the pump if crap enters the system…||1||Amazon|
|Elbow Adapter||90° angle to connect Silencer Kit (as needed)||1||Amazon|
|Shurflo Silencer Kit||Reduce noise from pump vibration||1||Amazon|
|ON/OFF switch||“Emergency” water pump switch||1||Amazon|
|Fitting, “Tee”: 1/2″ PEX to 1/2″ PEX to 1/2″ PEX||To split the PEX pipe for sink & shower||1||Amazon|
|Valve: 1/2″ PEX||We turn this valve off in winter and drain to prevent freezing (we don’t use the shower or bike wash in winter)||1||Amazon|
|SINK AND GREY WATER|
|Dometic VA7306AC Sink||The sink…||Campervan-HQ|
|Swivel Fitting: 1/2″ FPT to 1/2″ PEX||To connect the PEX pipe to the sink||1||Amazon|
|End Cap: 1/2″ FPT||To cap the unused hot water sink fitting (essential!)||1||Amazon|
|Drain||The sink does not include the drain, so make sure to order this!||1||Amazon|
|Camco Flexible Drain||1||Amazon|
|Wye & Valves||To direct grey water into aqua-tainer or through-floor||1||Amazon|
|Quick-Connect||To easily detach the aqua-tainer for dumping||1||Amazon|
|Hose Clamps, Worm-type||To ensure the garden hose doesn’t slip out of the aqua-tainer||1||Amazon|
|Aqua-Tainer||4 gallons grey water tank||1||Amazon|
|EccoTemp L5||On-demand propane shower||1||Amazon|
|Swivel Elbow Fitting: 1/2″ FPT to 1/2″ PEX||To install the water valve||1||Amazon|
|Valve: 1/2″ PEX||Water Valve||1||Amazon|
|Valve: 1/2″ FPT to 3/8″ Flare||Propane Valve. See our Propane System article for more.||1|
|Spray Faucet with coil hose||1||Amazon|
|Swivel Fitting: 1/2″ FPT to 1/2″ PEX||To connect the PEX pipe||1||Amazon|
|End Cap: 1/2″ FPT||To cap the unused hot water sink fitting (essential!)||1||Amazon|
|Fitting, “Tee”: 1/2″ PEX||This is required if, like us, installing both the shower & the bike wash||1||Amazon|
|Fitting, Elbow: 1/2″ PEX||The PEX pipe can bend 5″ radius max. For tighter turns, use this elbow.||As Required||Amazon|
|Bend Support||This has less restriction than an elbow||As Required||Amazon|
|PEX Tubing, 1/2″||a.k.a. pipe, hose…||As Required||Amazon|
|Fitting, MISC||We can’t possibly list all the fittings you might need for your installation! Here is the complete SharkBite catalog.||SharkBite Catalog|
|PEX Cutter||PEX tubing can be cut with a carpenter’s knife, but this tool will make your life easier||1||Amazon|
2.1- Fresh Tank Anatomy
2.1.1- Fill Port
You guessed it, the fill port is used to fill the tank. While motorhomes and most pro-built campervans have a port outside the van to fill the tank, we don’t because we don’t want the van to look like an RV; we like our van to look like a normal cargo van from the outside (people refer to that as being “stealth”). So here’s how we fill:
We carry a 50 feet hose (lead free and BPA free) to fill our fresh water tank. If we had to start over, we might consider carrying two 25 feet hoses, because 25 feet is what we need 95% of the time and using a longer hose slows down the process (more length adds flow restriction). So for the rare cases when we need over 25 feet, we could connect the two hoses together...
Because the hose end may be too large to fit in the fill port of the water tank, the use of this neat “Water Tank Filler” from Camco is handy. Plus, the Water Tank Filler has an integrated shut off valve, so the pressure can be turned off instantly when the tank is almost full (no spill), making the fill process a one-person job:
The tanks we recommend (see “Water Tank Links” table above) have 15/16″ inner diameter fill holes (no threads). We plug it using this test plug:
2.1.2- Water Pump Port
The tanks we recommend (see “Water Tank Links” table above) have 1/2″ NPT female outlet ports (so a 1/2″ NPT male fitting is required).
2.1.3- Drain Port
The tanks we recommend (see “Water Tank Links” table above) have 1/2″ NPT female outlet ports (so a 1/2″ NPT male fitting is required).
2.1.4- 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 braking 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 ports (so a 1/2″ NPT male fitting is required).
See section 1.3.1 for picture.
2.2- What Size?
It totally depends on your usage and how many days of 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 gallon tank every 4-5 days in summer (depending on showers). Every 7-10 days in winter (we shower in aquatic centers or gyms and try to fill our 1L water bottles as often as we can in public places).
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!
2.3- Inside or Outside the Van?
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 the van 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 in doing this.
- That’s food for thought, we don’t have any installation layout/details for that…
2.4- Wheel Well Water Tank
Wheel well water tanks are a thing now, and we wish that option existed when we built our van! As the name suggests, wheel well water tanks are shaped so that they embed over the wheel well. We see several benefits over the “old-school” rectangular tanks:
Decrease the waste of space, increase the living/storage space. That’s the name of the game when building a van!
Lower Center of Gravity
The fresh water tank carries a significant weight; lowering the center of gravity will improve the handling of the van.
No need to build a raised shelf to clear the wheel well.
Northwest Conversions has the largest offering of wheel well water tanks, and they keep adding new products it’s hard to keep up 🙂 Most of the tanks are designed for the Sprinter (fits tight over the wheel well), but work great with the Ford Transit (leaves space for insulation between the wheel well and the tank), and work with the ProMaster too (tank must be raised 3.5 in):
There’s also has a few other van-specific interesting options:
3- 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 is no excrement or chemicals in grey water.
2. Aqua-Tainer x Garden Hose Adapter
Aqua-Tainer threads are proprietary, no existing fitting will fit. So we designed and 3D printed our own! Buy in our Store.
3. Garden Hose Quick-Connect
4. Camco Sink Drain
Easy flexible sink drain. Buy on Amazon.
5. 2-Way Valve (optional)
To divert water into the grey tank, or through the floor. Buy on Amazon.
6. Garden Hose
Through-floor drain. Buy on Amazon.
3.1- What Size?
That depends on how often you don’t mind having to empty it. As a guideline, we empty our 4 gallon grey water tank almost every day:
- 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, we don’t have to empty our grey water tank every day…
3.2- 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!
The lowest temperature we have experienced so far is -31°C (-24F), and we could still use the water system! 🙂
5.1- Diaphragm Pump
A diaphragm pump keeps the water system pressurized at all times. It means having running water just like
at home in a house.
The pump has no on/off switch. It starts automatically when the pressure drops, and it shuts-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.
One of the most common and reliable diaphragm pumps out there is made by Shurflo:
5.1.1- Connecting The Pump
5.1.1- Electrical Wiring
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. It 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 cycles 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 schrader 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.
7.1- For Pressurized System
Pretty much any sink will do. We have 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. The only downside we found is that the foldable faucet is in the way when washing/rinsing large items (such as full size plates or pot/pan); we wish it was located further back so we didn’t have to swing it around.
Edit 2020: Looks like Dometic is now making this sink square (VA8005 model) instead of round (VA7306AC model):
A newer option that recently caught our attention! It looks super classy, functional, and also convert as a shower head!
- 52″ extra-long pull-out head (see demo in video).
- Made from 3mm stainless steel coated with a thick layer of oil-free nanotechnology coating resistant to staining.
- Removable cover (can be used as a cutting board!).
- Cold & hot water fittings: 1/2″ NPT.
- Drain size: 1-1/2″ fitting (strainer not included).
- Exterior dimensions: 450mm x 390mm (17.72″ x 15.35″).
- Interior dimensions: 380mm x 347mm (14.96″ x 13.66″).
- Cutout: 420mm x 360mm (16.54″ x 14.2″).
- Depth: 230mm (9″)
We don’t have hot water in the sink, and we’re totally OK with it: 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.
8.2.1- Tankless Water Heater (On-Demand)
As the name suggests, a tankless water heater has no tank. Water is heated instantly on-demand, so it can provide a continuous flow of hot water. It’s super-efficient since it doesn’t have to keep water hot all day.
8.2.2- Water Heater With Tank
Atwood has a wide range of water heater models, but the one that catches our attention is the G8A-6E model:
- 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’s website for all their available models: http://www.atwoodmobile.com/water-heaters.asp
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 an 11 liter water tank integrated. Fun fact: it’s over $3K…
9- Bike 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 the “Dog Poop Wash” as it has become the primary use…
Let’s get straight to the point, PEX tubing is what you want.
- PEX tubing has become the standard for houses and RVs.
- It’s cheap and readily available in any hardware or RV store.
- It comes in red/blue color to differentiate hot/cold side (both colors have 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, and 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 under constant sun exposure.
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, a 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 equally 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.
10.2.3- Compression Fittings
The disadvantage with clamp/crimp is that it might be impossible to operate the tool in tight spaces. In that case, you could use Flair-it compression fittings as they require no tool for installation. We personally haven’t tried them, but they’re quite popular in the RV industry. Flair-It fittings come in a variety of shapes and functions:
10.2.4- 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 tried them and when we pressurized the system, many fittings had slow leaks.
- Slow leaks are the worst because they’re hard to notice and could create damage in the long run… Why did we have 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 creates scratches on the outside surface of the tubing…
- O-Rings dry and lose efficiency in the long run.
- Some people reported having no issue at all after many years, but we think they are too sensitive to install, to outside tubing surface conditions and to O-ring deterioration. We’re not 100% confident, so we pass (we would be OK with them for temporary repair or outside installation).
10.2.5- Threaded Fittings
For all threaded plastic fittings:
- Do not use Teflon tape or Teflon paste! These are lubricant, not sealant, designed for metal fittings and they will promote over-tightening of plastic fittings = cracks = leaks.
- Don’t over-tighten: finger tighten plus one or two turns.
- Use non-hardening, plastic-safe, non-toxic thread sealant (not lubricant). It’s a paste that does not dry and can be removed easily (not permanent).
- We did not use thread sealant on the Shurflo fittings attached to Shurflo appliances (pump & accumulator).
Compatible with plastic fittings (PVC, CPVC, ABS, Nylon). Non-toxic (OK for potable water). Non-hardening. See product info (pdf).
11.1- To Winterize
When water turns from liquid into ice, its volume expands by approximately 9%; as a result, any water trapped into a component that freezes will crack said component.
In an RV, it is almost impossible to completely drain the water from everything. The best way to achieve this would be to use an air compressor to blow out the system, but it’s not guaranteed to work… That’s why most people winterize their water system with antifreeze.
Our water system, however, is quite simple; there are few components, and these components are all accessible. So it can be winterized by draining all the water and without adding antifreeze. Empty the water tank completely and, with the pump activated, open each faucet independently (sink, hot shower, bike wash) for a rough “pre-drain”. Disconnect the water pump, the accumulator, the hot shower (Eccotemp), and the bike wash. Water will come out, so have a large bowl and some towels ready! If you can, take all these appliances inside your house for the winter (hey, the removal should only take a few minutes of your time it’s not that bad!). If removing them is not possible, blow out with compressed air to drain them well. Be extra careful with the hot shower (Eccotemp), it’s much harder to drain because of the heat exchanger (we’d really take this one inside the house for the winter..).
11.2- Or To Not Winterize
Since we usually live full-time in the van and all our components (pipes, water heater, fresh water tank, etc.) are located inside (warm-side), we can use our water system ALL-YEAR, sweet! We even used it when it was -24F (-30°C). We only take the precaution of winterizing the bike wash / shower at the back of the van; this area can freeze occasionally (it’s far from any heat source), so we avoid taking any risk and drain it.
13.1- Keep it simple!
For a majority of people, monitoring the level of the tanks just by looking through them does the job. That’s what we did for the first year or so we lived full time in our van; it worked just fine, and it’s the cheaper solution.
13.2- Simarine Pico
After a year or so living full time in our van, we decided to upgrade for a fancy monitoring system. The Simarine Pico is not only sexy, it is also packed with cool features: battery monitoring, tank level monitoring, temperature sensors, inclinometer, etc. We appreciate the tank level feature (fresh tank, grey tank & Nature’s Head liquid tank) and the low/high level alarm. It would be hard to go back after getting used to it…
14- How to sanitize the Water System
Because we live full time in our van, our water system is constantly refreshed (we fill our tank approximately every 4 days). Therefore, we sanitize our tank every six months. If you must leave your van alone for a week or two without draining the system, consider sanitizing before using it (especially in a hot climate!).
1- Prepare a bleach solution
15.1- Tank Installation
The tank is installed above the wheel arch:
When the tank is full, there is noticeable “bow” on the unsupported side of the tank; we therefore added a wood support to counterbalance the bow (the straps alone won’t help). Note that the wood support must go across the entire height of the tank (from bottom to top) to be effective (otherwise the strap will flex):
15.2- Water Pump, Accumulator & Plumbing Installation
Water pump & accumulator:
We built a “shield” for the pump and accumulator and installed the switch on it:
It looks like this with the “shield” on:
This is the tubing near the pump and the accumulator:
- Our tank has a water pump port at the rear; unfortunately this tank is not made anymore… The tanks we suggest have all ports on the same side.
- To save space, we used a Shurflo 90° elbow adapter fitting between the strainer and the silencer kit.
And this is the tubing where it splits toward the bike wash / shower:
15.3- Sink and Grey Water Tank Installation
This is our grey water tank:
Meanwhile in China:
15.4- Bike Wash Installation
15.5- Hot Shower Installation
To connect the cold water (blue PEX tubing), we used a swivel-elbow adapter followed by an elbow (per our water diagram); this way the valve (which acts as the shower handle) is easily accessible and is routed around the propane valve (see also following picture for a different view angle).
16- On Second Thought...
- October 2017 : One month living full-time in the van! We talk about the water system in our “First Month on the Road” article: faroutride.com/first-month/
- December 2017: We modified our grey water system so we can dump water directly through the floor (or in the grey water tank).
- June 2018: We traded the Mr Heater BOSS for an EccoTemp (see justifications above in this article). We also re-plumbed our system using PEX tubing instead of braided vinyl tubing (because that’s the proper way to do it).