Van Plumbing Systems Overview
Plumbing in a van is simpler than a house but still needs to be done right. A well-designed system gives you running water at the kitchen sink, a shower (if your build includes one), and sometimes a toilet — all off-grid.System Components
Fresh Water Tank
Holds your clean, drinkable water. Capacity ranges from 15 gallons (basic) to 40+ gallons (premium). The tank is usually mounted under the van or inside a cabinet, and a 12V pump pressurizes the system to deliver water to your faucet.Grey Water Tank
Collects used water from your sink and shower drains. It’s not sewage — it’s soapy water. Grey water tanks are typically the same size or slightly smaller than your fresh tank. Most grey tanks are mounted underneath the van with a drain valve for dumping at RV dump stations.Water Pump
A 12V diaphragm pump (like the Shurflo or Seaflo) pressurizes your water lines. When you open a faucet, the pump detects the pressure drop and kicks on. When you close the faucet, it shuts off. Simple, reliable, and runs off your electrical system.Water Heater
If your build includes hot water, you’ll have a small tankless water heater (propane-fired, like the Camplux) or a small tank heater (2–6 gallons). Tankless units save space and heat on demand. Tank units store hot water but take up more room.Plumbing Lines
Most van builds use PEX tubing with push-fit or crimp connections. PEX is flexible, freeze-resistant (to a point), and easy to work with. We don’t use copper in vans — it’s rigid, heavy, and prone to vibration fatigue.Fixtures
Kitchen faucet, shower head (if applicable), and any additional fixtures like an outdoor shower. Compact RV-style fixtures work best for space efficiency.System Types by Build Tier
| Tier | Fresh Tank | Grey Tank | Hot Water | Fixtures | Plumbing Budget |
|---|---|---|---|---|---|
| Basic | 15–20 gal | 10–15 gal | None or portable | Kitchen sink only | 3.5K |
| Standard | 25–35 gal | 20–25 gal | Tankless (propane) | Kitchen sink + indoor shower | 7K |
| Premium | 35–50+ gal | 30–40 gal | Tankless or tank heater | Full bathroom (sink, shower, toilet) | 18K |
How It All Connects
The flow is straightforward:- Fresh tank → 12V pump → PEX lines → faucet/shower
- Drain → grey water lines → grey tank (under van)
- Water heater (if equipped) sits in-line between the pump and the hot water faucet
Common Mistakes
- Undersized grey tank — If your grey tank is smaller than your fresh tank, it fills up before you run out of fresh water. Size them to match.
- No P-traps on drains — Without a P-trap, sewer smell from the grey tank comes back up through your drain. Simple fix, often forgotten.
- Rigid pipe instead of PEX — Vans vibrate. A lot. Rigid connections work loose over time. PEX flexes with the van.
- Inaccessible connections — Put your connections where you can reach them. A leak behind a sealed wall panel is a nightmare to fix.
- No winterization plan — If you’re in cold climates, water lines freeze. You need a way to drain the entire system, or run heat tape on exposed lines.
Next Steps
- Water Systems Deep Dive — Fresh, grey, and black water details
- Plumbing Sizing Guide — Tank and pump sizing for your build
- Get a quote for your plumbing build →