Preparing Your Motorhome for Winter Storage: The Checklist

Winter Storage Guide

A practical guide from Bedam Leisure — caravan & motorhome specialists

Preparing your motorhome for winter storage comes down to five jobs: get every drop of water out of it, keep both batteries charged, stop damp forming inside, look after the base vehicle, and make it harder to steal. Give it an afternoon in October and the van you collect in March is the one you parked.

The reason this matters more for a motorhome than for a caravan is the front half. A caravan going into storage is a box on a chassis, and once it is drained and ventilated there is very little left to go wrong. A motorhome is a diesel van as well as a home, and a diesel van that sits unused for five months develops its own set of problems — flat starter battery, flat-spotted tyres, seized handbrake, mice in the wiring loom — none of which a habitation checklist covers.

So this is the motorhome version. We have written separately on laying a caravan up; everything below assumes you are storing a coachbuilt, van conversion or A-class and that it will not move again until spring.

1 The base vehicle

The half a caravan doesn't have

Fill the fuel tank before you park it. A part-empty tank has a large air space above the diesel, that air carries moisture, and moisture condensing on cold tank walls over a winter is what feeds diesel bug. Full tank, less air, less water. If your van takes AdBlue, leave a reasonable level in it rather than running it to empty — it freezes at around minus eleven, thaws again with no harm done, and a tank left dry for months is more likely to give you a sensor fault in spring than a full one is.

Set the tyres to the laden pressure on the plate, not to something soft, and if you can move the van even a couple of metres every few weeks, do — that alone is what prevents flat spots. Park on hardstanding rather than grass where there is a choice, because grass pushes damp up under the van all winter.

Leave the handbrake off and chock the wheels instead. A cable handbrake left applied for five damp months is the classic spring phone call: the shoes bond to the drums and the van will not move. This only works on level, private ground where the storage site allows it, so check before you rely on it.

Don't idle it on the drive. Ten minutes of idling once a month warms nothing properly, puts unburnt fuel past the bores and never gets the exhaust hot enough to dry out. Either drive it for half an hour so everything comes up to temperature, or leave the engine alone and deal with the battery properly instead.

Last job under the bonnet: mice. Take every crumb, packet and bar of chocolate out of the van, check the engine bay for nesting material, and if your storage is rural, be aware that rodents chew wiring insulation and heater hoses. It is the single most expensive thing that happens to stored motorhomes, and it costs nothing to make the van boring to a mouse.

2 Batteries

You have two batteries, and neither looks after itself

This is where motorhomes differ most. The leisure battery runs the habitation side and will slowly discharge through the alarm, the tracker and the control panel's standby draw. The engine battery has its own parasitic load from the ECU and immobiliser, and it is usually the one that is dead in March — because most people remember the leisure battery and forget the starter.

A flat lead-acid battery does not just need charging, it sulphates, and a battery left flat over a winter often never gets its capacity back. Either take both batteries out and keep them somewhere cool, dry and on a charger, or leave them in and keep them topped up where they sit.

If you are running lithium, read the manufacturer's storage note before you do anything else. Most lithium batteries prefer to sit at a partial state of charge rather than at 100%, and some have a low-temperature cut-off that stops them charging below freezing at all — which makes a solar panel pointless in January unless the battery is heated. There is more on all of this in our guide to leisure battery care, charging and going lithium, and the chargers and panels live in solar & battery.

3 Water and gas

Drain it, all of it, on a level pitch

Freezing water is the one job with no second chances: a split Truma boiler or a cracked pump body is a four-figure spring. The full method — fresh tank, waste tank, water heater, all taps to mid position and open, shower hose drained and hung down, filter cartridge out, pump run dry, waste valves left open — is set out step by step in our drain down and frost protection guide, and it is worth following it in order rather than from memory.

Two motorhome-specific points. Drain on the pitch you will leave it standing on, because a van drained level and then parked nose-down keeps a litre in the back of the tank. And if you have a wet central heating system — an Alde, or a Truma with a wet circuit — that loop does not get drained; it stays full of glycol and the glycol is what protects it. Check its strength and its age before winter, not in spring: our guide to caravan and motorhome antifreeze covers which fluid goes in which system and how much.

Gas: turn the cylinders off at the valve, not just at the panel. Many storage sites insist bottles are removed altogether, and there is a good argument for taking them home anyway — it is the easiest thing to steal off a stored van. If you are using the van through the winter rather than storing it, the fridge vents are worth a second look.

Leave the fridge off and open. Switch it off at the panel, clean it out, dry it, and prop the door on its travel catch. A fridge closed and damp for five months grows mould on the seal and comes out smelling of it.

4 Damp, cover and security

Air moving, water off, van boring to look at

A sealed motorhome makes its own weather. Every damp towel and every wet awning has to go somewhere, and it condenses on the coldest surface it can find — usually a cab window or the wall behind a locker. So the instinct to seal it up tight is exactly wrong. Leave the rooflights on their vent setting, never block the fixed low-level vents, open every locker and wardrobe, stand the cushions on edge, lift the mattress, and put moisture traps at both ends. Cab blinds and the windscreen are worth a wipe and a dry before you shut the doors — cab glass is the biggest cold surface in the van.

Then the cover, and it has to breathe. A plastic tarpaulin traps moisture against the panels and does more damage than the weather would. Size it on the van's overall length including the towbar, bike rack and any rear-mounted spare.

On security, the storage site does more for you than any single product: a CaSSOA-rated compound usually earns a lower premium than a driveway. Beyond that it is layers — a steering lock people can see from the gate, a tracker if the van is worth it, and nothing of value left inside. Take the satnav, the leisure battery charger leads and anything with a screen home with you. More options are in security & alarms.

Common questions

Should I start the engine over winter?

Only if you can drive it for twenty to thirty minutes so the engine, gearbox and exhaust get properly hot. A short idle on the drive does more harm than good. If you cannot drive it, leave the engine alone and keep the batteries charged instead.

Do I need to take the batteries out?

No, as long as they are being charged where they sit — mains hook-up, a solar panel or a maintenance charger. Take them out if the van has no power at all and you cannot fit solar; store them charged somewhere cool and dry and top them up every six to eight weeks.

Is a cover worth it, or does it cause damp?

A breathable cover is worth it: it keeps rain off the seals and UV off the sealant and the graphics. A non-breathable plastic sheet traps moisture against the panels and will cause damp. Fit it dry, and check the straps after the first gale.

Can I leave a motorhome on the road over winter?

Only if it stays taxed, insured and has a valid MOT — you cannot SORN a vehicle kept on a public road. Many councils also restrict long-term parking of larger vehicles, and an unattended van on a street is the easiest target there is.

What should I do first in spring?

Sanitise and refill the water system, check tyre pressures and look for flat spots, and charge both batteries fully before you turn a key. Our de-winterising guide works through it, and it is the right moment to book a damp check and habitation service.