How to De-Winterise Your Caravan or Motorhome for Spring

Spring Recommissioning Guide

A practical guide from Bedam Leisure — caravan & motorhome specialists

There's a particular kind of optimism that comes with opening the van door for the first time after a winter shut down. There's also, quite often, a smell. De-winterising properly is what separates a first trip that goes to plan from one where you discover the pump's dead and the water tastes like a swimming pool — three hours from home, on a Friday night.

Recommissioning isn't complicated, but the order matters. Do it in the wrong sequence and you'll find yourself refilling a system you're about to drain again, or firing up a boiler with no water in it. Here's the order we'd work in, and the things we see go wrong most often.

1 Walk-round first

Look before you switch anything on

Before a single tap or switch gets touched, walk the van slowly with a torch. You're looking for the things that happened while you weren't watching: green algae streaks down the sides, a soft patch or bulge in a panel, perished mastic around windows and lockers, and — the big one — evidence of anything living in there. Mice will chew wiring insulation over a winter and it is genuinely dangerous, so check under the seats, in the gas locker and around the heater ducting.

Check your tyres properly at this stage too. A van sat still for five months will have lost pressure, and sidewalls can develop flat spots and fine cracking that you simply won't see unless you get down and look. Tyre age matters as much as tread depth on a leisure vehicle, because they usually time out long before they wear out.

2 Water system

Refill, then sanitise — in that order

This is where most of the work is, and where most of the mistakes happen. Start by closing everything you opened in the autumn: all the drain taps, the low-point drain, and the boiler drain valve. Then walk the van once more and check you've actually got them all, because there is always one hiding behind a locker panel.

Now fill and sanitise. A tank cleaner does two jobs: it kills off the bacteria and biofilm that have been quietly growing in the pipework since October, and it clears the flat, plasticky taste that stagnant water leaves behind. Fill the system, dose it, run every tap — hot and cold — until you can smell the cleaner coming through, then leave it to dwell as the label instructs before flushing thoroughly. Running the taps is the step people skip, and it's the step that matters: cleaner sitting in the tank does nothing for the two metres of hose between the tank and your kitchen mixer.

Prefer a traditional formula? The Elsan 1L Fresh Water Tank Cleaner (£16.99) is the tried-and-tested option for shifting algae and bacteria from tanks and pipe runs.

While the system is empty, this is the moment to deal with the parts that don't survive winters well. Submersible pumps are the classic spring failure — they sit in a damp locker for months and the first you know about it is a whirring noise and no water. The O-rings on Ultraflow pistol connectors are the other one; they go hard, and you get a fine spray at the connection instead of pressure at the tap.

3 Gas

Check the dates, not just the connections

Gas is the one part of recommissioning where "it worked last year" isn't good enough, because LPG hoses fail by age rather than by use. Rubber pigtails carry an expiry date moulded or printed on them — usually shown as "EXP DATE" followed by a year, which is five years from manufacture, not from the day you fitted it. Truma and GOK hoses are typically rated for ten. Regulators should be replaced at least every ten years regardless of how well they appear to be working.

So: find the date on your pigtail. If you can't read it, or it's past, replace it — they're inexpensive, and a perished hose in a sealed gas locker is not a risk worth carrying. While you're in there, check the hose visually for cracking, swelling, abrasion and discolouration, and make sure it isn't kinked or under strain when the cylinder is in position.

Replacing the regulator too? The Truma MonoControl CS 30mbar (£155.99) has an integrated crash sensor and mounts vertically or horizontally — the usual single-cylinder upgrade. Any work on the fixed gas installation itself should be done by a qualified engineer.

4 Power

Battery, then everything that runs off it

If your leisure battery has been on a maintainer all winter, it should come back gratefully. If it's been sitting disconnected in a cold locker since October, be realistic — a lead-acid battery left flat over winter has probably sulphated and won't hold charge no matter how long you leave it on the charger. Test it under load before you rely on it, not by looking at a resting voltage in the sunshine.

With the battery live, work methodically through everything that depends on it: interior lights, water pump, the 12V sockets, the fridge on all three power sources, the heating, the alarm and tracker if you have them, and every smoke and carbon monoxide alarm in the van. Alarms have batteries of their own and they die silently over a winter. It takes ten minutes and it's the cheapest safety check you'll ever do.

5 Outside

Clean it, then look at it again

Washing the van isn't vanity — it's how you find things. Green algae and black streaking come off easily enough with a proper wash brush and a dedicated cleaner, and once the roof and walls are clean you can actually see the state of your seals. Go along every seam, window frame, rooflight and locker door and look for mastic that's cracked, lifted or gone chalky. Finding a failed seal in April and dealing with it costs a tube of sealant. Finding it in October, after six months of rain has been getting behind it, costs a great deal more.

Awnings deserve the same treatment. Pull yours out on a dry day, check it over, clean off anything that grew on it in storage, and re-proof it if water has stopped beading — far better to find a leaking seam in the garden than on a pitch in the rain.

For plastics, trim and vinyl, the Fabsil 500ml Universal Cleaner (£8.99) is a sponge-on formula that lifts ingrained dirt without stripping the finish.

One last thing: book the habitation check

Everything above is what you can sensibly do yourself. What you can't do at home is a proper habitation service — a gas tightness test, appliance combustion checks, ventilation and a full damp survey with a calibrated meter at every documented test point. Most manufacturers require an annual habitation check to keep the water-ingress warranty valid, and it's the only reliable way of catching damp while it's still a reading on a meter rather than a soft floor. Spring is exactly the right time to get it in the diary, before the workshops fill up.