Campervan Winterisation Guide UK 2026 – Stay Warm in Freezing Conditions

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The ultimate campervan winterisation guide for UK winters. How to stay warm, dry, and comfortable in freezing conditions — from 5kW diesel heaters to condensation prevention.

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Table of Contents

• Why Winterisation Matters
• Heating Options Compared
• Condensation Prevention
• Electrical Management in Winter
• Water System Winterisation
• Weatherproofing the Van
• Practical Winter Tips
• Common Mistakes

Why Winterisation Matters

Most campervan conversions work beautifully in summer. But the UK winter — wet, dark, and windy — exposes every gap in a DIY build. The difference between a comfortable winter van and a miserable one usually comes down to three things:

1. Heating — not glamorous, but the single most important winter upgrade
2. Condensation management — wet carpet in December is miserable
3. Electrical reliability — lights and fridge need to work when it's -5°C outside

Heating Options Compared

5kW Diesel Heater (The UK Standard)

Cost: £150-£300 (China import, UK seller)

Performance:

• Heats a Transit Custom from 0°C to 20°C in 10-15 minutes
• Uses diesel from the fuel tank (or separate 5L tank)
• Fuel consumption: 0.2-0.4L/hour
• Weight: 4.5kg
• Noise: ~45dB (like a hairdryer)

Pros: Unbeatable value, reliable, cheap to run Cons: Needs exhaust pipe, gets hot outside, draws O2 from van

Our verdict: Essential. No alternative comes close for the price.

Diesel Fridge (Keep food from freezing)

Your standard Dometic or Thetford fridge will stop cooling below -10°C. But food inside can freeze even if the fridge is running.

Solutions:

• Move fridge to a warmer part of the van (near the engine)
• Wrap in insulation foam
• Use a heated trunk for frozen items

Electric Heater (If you have shore power)

• 500W to 1kW small Electric heaters
• Great for pitched campsites where you have electricity hookup
• Not viable for off-grid use (draws too much battery power)

Condensation Prevention

The problem: You breathe, cook, dry clothes — all inside a sealed metal box. That moisture has to go somewhere. Usually: your carpet.

The solution:

1. Insulation (already installed) – prevents cold surfaces from condensing moisture
2. Ventilation – keep windows slightly open (even when raining)
3. Dehumidifier – Dometic or compact Electric dehumidifier (£30)
4. Jaffle bags – Dry your clothes in them
5. Use the roof vent – makeshift fan always on
6. Don't dry clothes inside – use a hanging line outside

Signs of bad condensation:

• Dripping windows
• Wet carpet
• Musty smell
• Mold in corners

Electrical Management in Winter

Winter kills battery capacity. A 100Ah LiFePO4 battery in 0°C stores about 80% of its summer capacity. In -10°C, it's closer to 60%.

Key winter upgrades:

• Battery heater wrap (Battle Born £30)
• Solar panels stay on – even in winter they produce 30-50% of summer output
• LED lights – essential for long dark evenings
• Inverter usage – limited to 300W in winter

Power budget (winter):

With 200W solar, this is achievable even in December.

Water System Winterisation

Pipes freeze at -2°C. To prevent frozen pipes:

1. Drain water tanks when not in use
2. Wrap exposed pipes in foam insulation
3. Use glycol solution for winter water

Tap/faucet tips:

• Keep a small gap open on the taps overnight
• Move hosepipe to a warm location
• If pipes freeze: thaw with a heat gun (not fire!)

Weatherproofing the Van

1. Seal gaps around windows, doors, roof vents
2. Check the roof for leaks (Primacover or similar)
3. Wind protection – build a windbreak with plywood panels
4. Floor insulation – add foam under the floor (warm feet!)
5. Door seals – replace worn weatherstripping

Practical Winter Tips

1. Park facing into the wind – less draft under the door
2. Sleep with your head towards the front – warmer, closer to engine heat
3. Use a wool blanket – synthetic fibers compress over time, wool stays fluffy
4. Keep shoes inside – freeze your boots, they won't dry overnight
5. Have a hot water bottle – preheat the bed with a hot water bottle
6. Eat high-calorie food – your body burns more calories staying warm
7. Get sunlight – open windows when the sun's out

Common Mistakes

1. Forgetting to ventilate – leads to condensation and a damp van
2. Overusing the inverter – drains battery fast in winter
3. Ignoring the battery heater – cold batteries die early
4. Using LED as primary light – LED light, LED flickers more in cold

Updated June 2026. Questions about winterising your van? Contact us. We're in a van right now in -5°C — happy to help.