From the start of the van design phase we knew we would have somewhat complex plumbing needs. We planned to have an indoor shower, an outdoor shower, a sink, and a hot water heater. We also decided to install water filters so we didn’t have to worry about water quality and would be able to fill water from unknown sources.

Here is a plumbing schematic showing the lines, components, and how everything fits together. There is also a list of parts used below.

Parts List:

Lets run through the main components of the system and how they were installed:

Fresh and grey water tanks:

To size our water tanks we tried to estimate our usage. Our goal was to be able to stay off grid for at least a week.

We’ve created a interactive water capacity calculator that you can use to estimate the water capacity needed for your build. You can edit cells and the spreadsheet will update automatically.

We estimated we would shower every other day for a bit over 2 minutes of water each (military showers), use a trickle of water for about one gallon of water per day to wash dishes, and drink about a half gallon of water per person per day.

A week of usage at this rate would be 38 gallons, and usually water tanks can not be drained to the last drop or filled up all the way so we needed a size over 38 gallons.

After traveling for over a year and a half we have realized our water needs vary a lot between seasons, activity levels and based on where we are. If we take showers every other day, we can usually last at least 8 days before needing to dump and refill water. If we aren’t showering as often, have access to outdoor showers, or accessible drinking water for daily consumption we have gone as long as 3 weeks before needing to refill water. The fastest we have needed to refill was 5 or 6 days, and we were taking showers almost every day as it was hot and we were exercising a lot.

Where to install the water tanks was another important decision to make before the tanks were purchased. There are a variety of sizes and shapes available. We elected to mount our grey water tank in the garage next to the wheel well and the fresh water tank above the wheel well. Installing the tanks inside the van was important for us because we knew we wanted to travel in freezing temperatures without the need for tank heaters or winterizing (and the associated lack of ability to use plumbing).

Finally, we had to ensure that the water tanks have enough inlet and outlet ports to provide for all our plumbing needs. For our grey tank, we needed to have a large outlet for draining the tank, a method to vent the tank, a large inlet for a sink gravity drain, and an inlet for the grey water from the shower. For our fresh tank, we needed a method to vent the tank, a large inlet for filling the tank, and a small outlet for the pressurized water lines.

We found two 46 gallon water tanks from Class A Customs (one for fresh water, one for grey water). They fit, were large enough, and were surprisingly cheap compared to some of the other options. We’ve had no issues with them and recommend their company’s products.

Roughing in the water tanks and checking fit/placement

Hot water heater:

We decided to go with an electric hot water heater and decided on the Isotherm SPA 20. It has a 750w heating element and a capacity of 20 liters. It can be hooked up to your engine’s coolant loop to heat the water while driving and uses a thermostatic mixing valve to set the hot water temperature. We chose to not connect it to the coolant loop to avoid any warranty issues with the van as well as the fact that we have the engine alternator connected to the house battery bank. With the alternator connected to the house bank, we can charge our batteries (or cover the hot water electrical demands while driving) which is quite similar to using engine coolant for heating the water (using coolant to heat the water should heat to a higher temperature and a bit more quickly, so there are some benefits to a coolant hookup).

We have found it takes anywhere from 45minutes to 1hr15mins to heat the water. The time depends on the ambient and water tank temperature. We have taken 4 hot showers back to back (a total of ~10-12 gallons of water used) and the water was still hot at the end.

The trickiest part of this installation was that we needed a BSP (British Standard Pipe) to NPT (National Pipe Thread) adapter as the hot water outlet is BSP thread and anything you purchase in the US will not be BSP.

We installed a check valve on the cold inlet of the hot water heater to prevent hot water from moving backwards through the lines. We also installed a method to drain the hot water heater in case we needed to remove all the water from our system (to winterize for example).

We used an existing body hole in the van for the drip/drain hose that is required and didn’t have to put any more holes in the body! A very small amount of fresh water drips out of this hose when the hot water is close to being ready, which is part of the hot water heater design.

Shower plumbing:

Our shower plumbing is a bit unique. We couldn’t use a gravity drain for the shower as we wanted our water tanks and all plumbing to be located inside the van. This is fairly common in marine settings and there are marine shower pumps which we adapted for our purposes.

We found a low profile shower drain, connected it to a Hepvo waterless trap, and then used adapters to convert the pipe to a 1/2” barb fitting. Braided nylon connects the drain to a stainless steel pre filter (which needs to be cleaned every few weeks), the pump, and then finally the grey water tank.

The fresh shower water runs to the mixing valve via 1/2” PEX with SharkBite fittings. There are ball valves before the mixing valve to shut off the flow to the cold and/or hot lines. We found a low flow 1.5 gallon per minute shower head which gives a satisfying shower, but saves precious water.

We find we can take 2-3 minute showers (amount of water run time) which helps us stretch our fresh water tanks as long as possible. We get wet and then turn off the water. Then we shampoo and soap up and then rinse off. We try to limit the amount of time the water is on when we don’t need it.

The shower drain and Hepvo waterless trap attached.

Sink Plumbing:

The sink drain connects to a Hepvo waterless trap and then gravity drains via PVC to the grey tanks.

The idea of a Hepvo waterless trap for the kitchen drain seems great and they save a lot of space, but we have had to clean them fairly regularly (every 3 months?) as food particles seem to intermittently keep them stuck open. We try to wipe our plates before cleaning them, but it doesn’t seem to be enough. Sometimes with the exhaust fan on full blast and the trap needing to be cleaned, some grey water odor will to enter the van via the sink. If I did it again, it might consider a standard P trap to minimize the maintenance. Interestingly enough the shower drain Hepvo has had no issues, so I think it must be larger food particles. Maybe we should try to find a finer sink drain pre-filter.

The sink fresh water comes in from PEX to 1/4” faucet adapters which connect to the faucet water lines.

Fresh tank plumbing:

Keeping with our theme of quasi stealth, we decided to located the fresh water fill on the inside of the van so there are minimal signs of an RV on the outside (some RVs have fresh water fill, propane vents, and shore power hookups on the outside).

The fresh water tank has 3 fittings on it. We have a 1 1/4” fresh water inlet which runs to the top right of the tank, a 1/2” vent on the top left of the tank, and a 1/2” outlet which is the bottom right of the tank.

We decided against a dedicated fresh water drain, as we can always just park on a hill and operate the fresh pump and drain the whole system further down the line. In 1.5 years, we haven’t had to drain the fresh tank or the water system once, so I think it was a good thing to skip.

Grey Tank Plumbing:

We have a bit of a unique grey tank plumbing set up. The sink uses a PVC gravity drain to the top right tank fitting (1 1/2” NPT). The shower drain uses a pump and flows via braided vinyl tubing to the top left fitting (1/2” NPT). The bottom left tank fitting is used for the grey water drain. A ball valve keeps it closed and the PVC goes through the floor to a threaded cap with bug screen. We store a drain hose under the rear bumper and thread it on to this threaded adapter under the van.

As we already used the traditional spot for a grey tank vent with the shower drain pump, we created a grey tank vent using the PVC drain line from the sink. This also doubles as an emergency tank overflow device, which we fortunately have not needed. There have been no issues with sink drainage with this setup.

Rear shower:

2 showers! It may seem excessive, but it is always nice to rinse off outside when its warm and not have to fill up the grey tank. What it is best for is washing off Billie (our dog), our bikes, wetsuits, or anything else that gets dirty while adventuring.

This was a fairly straightforward installation, just requiring running hot and cold water via PEX to the location of the shower and PEX adapters for connecting to the shower flexible lines.

Fresh water filters:

We wanted to ensure the water we used was safe and we wanted to have the ability to fill up from streams if necessary. We purchased this RV water package and installed it after the fresh water pump and accumulator tank.

The first filter (white) is a 1 micron sediment filter and the second filter is a 0.5 micron carbon filter. 0.5 micron filters should handle any cysts or bacteria in the water; the main things that get you sick when drinking untreated water. The 0.5 micron filter is also lead reducing.

We incorporated a bypass (valve below the filters) in case we decided to store the van in winter and use RV antifreeze in the lines. RV antifreeze should not be used with water filters.

Fittings, pipe, etc:

1/2” PEX for all fresh water lines and shark bite fittings for all PEX connections.
1 1/2” PVC for our sink drain and grey water drain/vent.
1/2” ID braided vinyl tubing for the shower drain run after the Hepvo waterless trap.
Many elbows, t fittings, ball valves, and barb fittings

If you have any questions or something isn’t clear, please feel free to comment below, send us an email or find us on Facebook or Instagram! We would love to hear from you!