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Plumbing Basics

Fresh water, waste water, pumps, and why your shower has no pressure.

Intermediate12 min read

Contents

1

Your Water System (Simplified)

A camper plumbing system is actually simple:

Fresh water tank → Pump → Pipes → Tap/Shower → Waste tank

That's it. The complexity comes in choosing components and routing pipes.

Tank sizes (UK recommendations):

Weekend: 20-40 litres fresh + 20L waste Jerry can
Week trip: 60-80 litres fresh + matching waste
Full-time: 100-120 litres fresh + 60-80L waste

Where to put the fresh tank:

Under the bed (most common)
Under the floor (underslung — needs insulation for winter)
In a cupboard (only for small tanks)

**Don't overthink this.** Most van lifers use 10-15 litres per day (washing up, drinking, basic washing). A 60L tank lasts 4-6 days. You can refill at any campsite, many petrol stations, or public taps.

2

Pumps: Pressure Switch vs Demand

Diaphragm pump with pressure switch (recommended):

Turns on when you open the tap (pressure drops)
Gives "normal" water pressure like at home
Shurflo Trail King or Flojet are the standards
Cost: £40-80
Slightly noisy (buzzing sound)
Needs an accumulator tank (£15-25) to stop pulsing

Submersible pump (budget option):

Drops into the water tank
Simple, cheap (£15-30)
Low pressure, no "home" feel
Fine for a basic setup

12V vs 240V:

Always use 12V in a camper. You're off-grid.
240V pumps need an inverter = wasted power

Pump sizing:

7-10 litres per minute is plenty for a tap
12-15 LPM if you want a decent shower
More than that is overkill and wastes water
3

Pipe Types & Routing

Pipe options:

**JG Speedfit push-fit** — the standard. Easy, reliable, no tools. Works with 12mm or 15mm pipe. This is what 90% of converters use.
**Copper** — traditional, lasts forever, but needs soldering and is rigid. Overkill for a van.
**Flexible reinforced hose** — good for connections to tanks and pumps. Use with jubilee clips.

Routing tips:

Keep pipes away from external walls (freezing risk)
Use pipe insulation on any runs near the van body
Drain-down valves at the lowest point (essential for winter)
Don't run pipes where you'll be drilling for furniture

The drain-down system:

UK winters freeze pipes. You NEED a way to drain the entire system:

1. Low-point drain valve (open it, water drains out)
2. Open all taps
3. Blow through the system with a hand pump
4. Done. Takes 5 minutes.

If you skip this and it freezes, your pipes WILL crack and you'll find out when everything thaws and floods your van.

4

Shower Setup (If You Want One)

Wet room (full shower):

Needs a sealed tray or GRP-lined cubicle
Takes 600-800mm of floor space (significant in a van)
Needs good ventilation (extractor fan or roof vent)
Waste water needs to go somewhere (tank or direct drain)
Realistic minimum van size: LWB high-roof

Outdoor shower (simpler):

Shower head through the back doors
Privacy awning or pop-up tent
Drain onto the ground (if biodegradable soap)
Much less space, much less faff

Waste water:

Grey water tank under the van (20-40L)
OR a Jerry can you empty manually
Use biodegradable soap (it's going into the environment)
Don't let grey water tank freeze

Hot water for shower:

Truma Ultrastore (gas/electric): proper hot water, expensive
Camplux portable gas heater: £100, works well
12V immersion heater: slow, power-hungry
Solar shower bag: free, works in summer, useless in winter
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