Plumbing Systems
Transit Van Plumbing: Freshwater, Greywater & Hot Water Systems
A well-planned plumbing system makes the difference between roughing it and actually living comfortably on the road. Here's how we approach plumbing in Ford Transit builds.
Transit van plumbing systems cost $2,000-$10,000+ depending on build tier, covering freshwater tanks (15-40+ gallons), greywater, hot water, and fixtures. The Transit's multiple roof heights and available AWD create unique plumbing considerations -- AWD models have less underbody space for tanks, and the gas engine's exhaust runs hotter than diesel, affecting line routing. Emery Custom Builds uses PEX tubing on every Transit plumbing install with winterization designed in from the start.
What Makes Transit Van Plumbing Different From Other Platforms?
The Ford Transit has a few characteristics that directly affect how we plan and install plumbing systems. If you've researched Sprinter or ProMaster plumbing, some of this will look familiar — but the details matter.
Transit-Specific Plumbing Factors
Roof Height and Layout Impact
The Transit comes in Low, Medium, and High roof configurations. For plumbing, the High Roof gives you the most flexibility — there's room to run lines above the ceiling or inside wall cavities without eating into headroom. Low and Medium roof Transits can still have full plumbing, but component placement needs more planning to keep everything accessible without wasting vertical space.
AWD and Underbody Clearance
If you have an AWD Transit, the transfer case and rear driveshaft reduce the underbody space available for external tank mounting. We can still mount tanks underneath on AWD models, but the tank size and shape options are more limited compared to RWD Transits. In some AWD builds, we mount the freshwater tank inside the van (under the bed platform or in the rear garage) to avoid clearance issues entirely.
Gas Engine and Heat Considerations
Unlike the Sprinter (diesel), the Transit runs a gas engine. The exhaust system generates more localized heat, which matters when you're routing plumbing lines or mounting tanks near the undercarriage. We keep all tanks and PEX lines away from exhaust components and use heat shielding where needed. This is something a lot of DIY builds miss.
How Do Freshwater, Greywater, and Hot Water Systems Work in a Transit?
Every van plumbing system has three parts: getting clean water in, heating it (if you want), and getting used water out. Here's how we handle each.
Freshwater System
Your freshwater tank feeds the kitchen sink, bathroom sink (if you have one), and shower. We size the tank based on how you'll use the van and how often you can refill.
- • Basic builds: 15–20 gallon tank, single sink, manual or electric pump
- • Standard builds: 25–35 gallon tank, kitchen sink, possible outdoor shower, 12V demand pump
- • Premium builds: 30–40+ gallon tank, full kitchen and bathroom sinks, indoor shower, accumulator tank for consistent pressure
We use food-grade polyethylene tanks with a city water inlet for hookups at campgrounds or RV parks.
Greywater System
Greywater is the used water from your sinks and shower (not toilet waste). It needs to go somewhere — either a tank you dump periodically or a direct drain valve for off-grid use.
- • Underbody tank: Most common. Gravity-fed from sinks, with a dump valve for emptying at RV dump stations.
- • Portable container: Simpler option for basic builds — a removable jug or tank under the sink that you empty manually.
We typically size the greywater tank to match or slightly exceed the freshwater capacity so you don't overflow before you need to refill.
Hot Water
Hot water is optional but makes a big quality-of-life difference, especially if your build includes a shower.
- • Tankless propane heater: On-demand hot water. Compact, efficient, and the most popular choice for Standard and Premium builds. Brands like Camplux and Girard are common.
- • Small electric tank heater: A 2.5-gallon 12V or 120V unit works for sink-only hot water. Slower recovery time but simpler install and no propane required.
- • Heat exchanger (engine coolant): Uses engine heat to warm water while driving. Free hot water, but only available after the engine's been running. Good as a supplement, not a primary system.
Why Is PEX the Best Plumbing Material for a Transit Van?
We use PEX (cross-linked polyethylene) tubing for all van plumbing runs. It's the industry standard for van conversions and for good reason:
- • Flexible: PEX bends around corners and through tight spaces without fittings at every turn — fewer connections means fewer potential leak points.
- • Freeze-tolerant: PEX expands slightly when water freezes inside it, making it far less likely to burst than rigid pipe. This matters for winter camping.
- • Lightweight: In a van where every pound counts, PEX is significantly lighter than copper or CPVC.
- • Color-coded: Red for hot, blue for cold. Makes troubleshooting and future maintenance straightforward.
We use crimp or push-fit connections (SharkBite-style) depending on the run, and secure all lines with insulated clamps to prevent rattling on the road.
What Toilet Options Work Best in a Transit Van?
There's no black water tank in a van conversion — that's an RV thing. Instead, we install self-contained toilets that don't need a sewer hookup.
Composting Toilet
- •No chemicals, no odor when maintained
- •Separates liquids and solids
- •Empty solids every 4–6 weeks (2 people)
- •Needs a small vent fan (12V, runs continuously)
- •Higher upfront cost (~$900–$1,100)
Cassette Toilet
- •Removable waste cassette — dump at any RV station
- •Lower cost (~$100–$300)
- •Uses chemical treatment fluid
- •Dump every 3–5 days (2 people)
- •Simpler install, familiar feel
Both work well. We install whichever fits your preference and budget. Most full-timers gravitate toward composting toilets for the lower maintenance cycle.
How Do You Winterize Plumbing in a Transit Van?
If you plan to camp in cold weather — or even store the van where it freezes — the plumbing system needs to handle it. Here's what we do:
- • Interior tank mounting: Keeping tanks inside the insulated living space protects them from hard freezes. This is the single most effective winterization step.
- • Insulated line runs: PEX lines that pass through uninsulated areas (like under the floor or through the van walls) get pipe insulation and, in cold-weather builds, self-regulating heat tape.
- • Drain valves: Low-point drain valves on both freshwater and greywater systems let you empty everything quickly when winterizing for storage.
- • Bypass valves: The hot water heater gets a bypass so you can pump non-toxic RV antifreeze through the lines without filling the water heater tank.
Even in Southern California, we recommend at least basic winterization capability if you plan to head to the mountains or travel to colder states.
How Much Does Transit Van Plumbing Cost by Build Tier?
Plumbing is one component of your overall build cost. Here's a rough breakdown of what to expect at each tier — materials and labor included.
Basic ($2,000–$4,000)
A functional plumbing setup that covers the essentials: kitchen sink, freshwater tank (15–20 gal), 12V pump, basic greywater collection, and PEX supply lines. No hot water or shower.
Typical components: Single sink, foot or electric pump, portable greywater container or small underbody tank.
Standard ($4,000–$7,000)
Everything in Basic, plus hot water, a larger freshwater tank (25–35 gal), matched greywater tank, and possibly an outdoor shower. Composting or cassette toilet.
Typical components: Tankless propane water heater, demand pump with accumulator, underbody greywater tank, PEX hot and cold runs.
Premium ($6,000–$10,000+)
Full plumbing system: indoor shower with proper drainage, large freshwater and greywater tanks (30–40+ gal each), tankless hot water, winterized lines, and composting toilet. Everything is insulated and secured for four-season use.
Typical components: Enclosed wet or dry bath, heat-taped lines, low-point drains, city water inlet, high-flow demand pump.
These numbers are rough guides — your actual plumbing cost depends on tank sizes, fixture choices, hot water method, and how much winterization you need. We break it all out in your quote so you know exactly what you're paying for. See our Transit conversion page for full build pricing.
What Do People Ask Most About Transit Van Plumbing?
How many gallons of freshwater can a Transit van carry?
Most Transit builds carry between 20 and 40 gallons of freshwater. The exact size depends on your build tier, available underbody space, and how long you want to go between fills. A 20-gallon tank is enough for about 3–4 days of conservative use. 30–40 gallons is more comfortable for full-timers or builds with a shower.
Do I need a hot water heater in my van?
It depends on how you plan to use the van. If you want hot showers on the road, yes — we typically install a tankless propane water heater like a Camplux or Girard. For basic builds where you only need hot water at the sink, a small 2.5-gallon electric water heater works fine and costs less.
Composting toilet or cassette toilet — which is better?
Neither is universally better — it comes down to your preferences. Composting toilets (like the Nature's Head) have no chemicals, no black tank, and less odor when maintained. Cassette toilets are cheaper upfront, simpler to install, and easier for people new to van life. We install both and can walk you through the trade-offs.
Can Transit van plumbing handle freezing temperatures?
With proper winterization, yes. We run PEX lines that handle expansion better than rigid pipe, insulate exposed lines, and can add heat tape to vulnerable runs. For the tanks, interior mounting protects against hard freezes. If you plan to camp in below-freezing weather regularly, we'll factor that into the plumbing layout from the start.
How much does plumbing cost in a Transit van conversion?
Plumbing costs range from roughly $2,000–$4,000 for a Basic build (simple sink and freshwater tank) up to $6,000–$10,000+ for a Premium build with hot water, shower, composting toilet, and winterized lines. The system you choose — and the tank sizes, fixtures, and heating method — drive the final cost.
Related pages: Transit Van Conversions · Plumbing Systems · How to Plumb a Van · Our Work
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