Campervan Plumbing, Gas & Heating
The Complete Comfort Guide

Turning a commercial panel van into a comfortable, off-grid home on wheels requires mastering your utility systems. Water, heating, and gas are the three core pillars that transform basic camping into a sustainable, nomadic lifestyle. Whether you are planning weekend trips along the UK coast or living in your van year-round, this guide covers essential technical choices and safety regulations.

1. Water Systems: Storage, Pumps, and Hot Water

Water autonomy dictates how long you can remain off-grid. Managing water in a compact vehicle requires careful planning to prevent leaks, winter freezing, and exceeding your vehicle's Maximum Technically Permissible Laden Mass (MTPLM).

Sizing Your Water Reserves: Fresh and Grey Water Tanks

On average, a water-conscious vanlifer uses 10 to 15 litres of water per day per person (drinking, cooking, washing up, and quick showers). For two people seeking 3 to 4 days of autonomy, an 80 to 100-litre fresh water tank is the ideal standard.

For grey water (wastewater from the sink and shower), a tank capacity equal to 70% to 80% of your fresh water tank is sufficient (e.g., 70 to 80 litres of grey storage for 100 litres of fresh water). To prevent foul odours, fit waste pipes with anti-odour water traps or dry membrane valves.

Tank Positioning & Weight Distribution

Water weighs 1 kg per litre. A full 100-litre tank adds significant weight to your chassis. To maintain safe handling:

• Lower the Centre of Gravity: Mount water tanks as low as possible (floor level or slung beneath the chassis).
• Distribute Axle Loads: Avoid placing heavy tanks behind the rear axle (the overhang). Position them centrally over the main axles.
• Freeze Protection: For winter use, install fresh water tanks internally. External underbody grey tanks should feature 12V insulation jackets and heating pads to prevent freezing.

Submersible vs. Pressure-Demand Diaphragm Pumps

Two pump systems deliver water from tank to tap:

• Submersible Pump: Sits inside the tank. It is quiet, affordable, and operated via microswitched taps. Opening the tap completes a 12V circuit to trigger the pump. Best for simple builds and compact micro-campers.
• Pressure-Demand Diaphragm Pump (e.g. Shurflo): Mounted externally, keeping the system pressurized (typically 1.5 to 2.5 bar). Opening a standard domestic tap causes a pressure drop that automatically triggers the pump. Essential for showers and water heaters. Always pair with an accumulator tank to absorb pressure spikes and smooth out flow.

Water Heating Options

• Gas Water Heater (e.g. Truma Ultrastore / Boiler): Heats water rapidly (under 20 minutes) with minimal battery draw. Requires a sealed flue venting directly through the vehicle bodywork.
• 12V / 230V Electric Water Heater (e.g. Pundmann): Uses excess solar power or alternator charging while driving. Requires a robust Lithium (LiFePO4) leisure battery bank.
• Engine Heat Exchanger (Coolant Calorifier): Uses surplus heat from the vehicle engine coolant while driving to heat domestic water via a plate heat exchanger.

2. Auxiliary Diesel Heating: Four-Season Comfort

While thermal insulation slows heat transfer, it does not generate heat. When ambient temperatures drop below 10°C, an auxiliary heater is required.

Why Diesel Heaters Lead the Market

Auxiliary diesel blown-air heaters (Autoterm, Webasto, Eberspächer) are the UK industry standard for panel van conversions:

• Direct Fuel Supply: Connects directly to the main vehicle fuel tank via a fuel pickup pipe.
• Space Efficiency: Eliminates the need to carry heavy gas cylinders solely for space heating.
• Fuel Economy: A 2kW unit consumes just 0.1 to 0.25 litres of diesel per hour.

Selecting Heater Output: 2kW vs. 4kW

Oversizing a diesel heater is a common mistake. Diesel heaters must run at medium-to-high power periodically to burn off carbon deposits. If oversized (e.g., a 4kW unit in an MWB van), the heater will constantly idle at its lowest setting, causing rapid carbon build-up (sooting up) and system lockouts.

For 90% of standard panel vans (up to L3H2 High Roof), a 2kW heater is optimal. Reserve 4kW units for extra-large box vans or uninsulated vehicles.

High-Altitude Compensation

Above 1,500 metres, thinner air contains less oxygen. Standard fuel delivery creates an over-rich mixture that clogs the combustion chamber with soot within days. Modern heater controllers (e.g., Webasto AirTop 2000 STC or Autoterm Comfort Control) feature an automatic pressure sensor (altitude mode) that reduces fuel pump pulses to maintain the correct air/fuel ratio.

3. Gas Installation: Cooking Standards & Safety

Gas installations in campervans must strictly adhere to BS EN 1949 standards for safety, reliability, and insurance compliance.

Propane, Butane, and Refillable LPG

• Butane: Stops vaporising at 0°C, rendering it unusable in sub-zero winter conditions.
• Propane: Operates down to -42°C, making it the preferred choice for UK vanlife year-round. Note: Propane cylinders must always be secured inside a dedicated, sealed gas locker.
• Refillable LPG Tanks (e.g. Gaslow / Underslung Tanks): Permanently mounted tanks fitted with an external filler neck, refillable at autogas stations across the UK and Europe.

Sealed Gas Lockers & Ventilation Standards

In accordance with BS EN 1949, gas cylinders must be housed inside a dedicated, gas-tight locker sealed from the main living area. Because LPG is heavier than air, the locker floor must feature a drop vent passing directly through the vehicle floor (minimum free area equivalent to 2% of the locker floor area, or 50mm–75mm diameter) to safely vent potential leaks outside. Access doors must incorporate a rubber compression seal and secure latches.

Gas Pipework and Pressure Regulators

UK and European regulations specify a fixed operating system pressure of 30 mbar:

• Rigid Pipework: Main gas lines must be constructed using seamless rigid copper or steel tubing with approved compression fittings (copper olives).
• Flexible Hoses: High-pressure rubber hoses are permitted only between the cylinder valve and the wall-mounted regulator (maximum length 400mm to 750mm).
• Flame Failure Devices (FFD): Every gas appliance (hob burners, ovens, water heaters) must feature a thermocouple safety device that shuts off gas flow if the flame extinguishes.