Winter Touring: Getting the Best from Your Truma or Alde Heating

Winter Touring Guide

A practical guide from Bedam Leisure — caravan & motorhome specialists

Winter touring is the best-kept secret in caravanning. Empty sites, frost on the fields, and a van that's warmer than most houses. But the difference between a brilliant cold-weather trip and a miserable one almost always comes down to the same thing: whether the heating system was set up properly before you left the drive.

The good news is that modern vans are genuinely capable. Truma has run a Combi down at −26 °C and still held +20 °C inside with the water system working. The kit is up to it. What usually lets people down is the gas supply, a drain valve nobody understood, or heating fluid that hasn't been changed since the van was new.

Here's how we'd get a van winter-ready — and midsummer is honestly the ideal time to sort it, while parts are in stock and you're not lying in a frozen gas locker with a torch in your teeth.

1 The gas

Butane will let you down. Propane won't.

This is the single most common winter failure we hear about, and it has nothing to do with the heater. Butane stops vaporising properly at around +5 °C. On a frosty morning you'll have a bottle that still feels heavy, still sloshes — and simply won't deliver gas. Propane keeps flowing far, far below anything a British winter will throw at you.

So the rule is simple: swap to propane before the cold arrives. In the UK that's the red bottle rather than the blue one. And because propane runs at a different pressure, it needs the correct regulator and the correct pigtail hose — you can't just clip a butane setup onto a propane bottle and hope.

The regulator itself can freeze. Right around 0 °C, traces of water in liquid gas can form ice or propane hydrate inside the regulator and choke the supply — even with a full propane bottle. Truma's EisEx regulator heater exists precisely for this, and it's why gas supply can fail on a damp night at zero rather than on a hard, dry frost at −8 °C.

2 Know your system

Blown air or wet heating — they behave differently

Almost every van falls into one of two camps, and knowing which you have changes what you do in winter.

3 Truma systems

Living with a Truma Combi in the cold

The part that catches people out is the FrostControl — the combined safety and drain valve on the water side. It is currentless and entirely mechanical, and it does exactly one thing: if the temperature at the valve drops to around 3 °C, it opens and dumps the contents of the boiler out through the drain socket. That's not a fault. That's it saving you from a split boiler.

Where it bites is on a cold morning when you're trying to refill. If the temperature at the FrostControl is below roughly 7 °C, the valve simply won't stay shut. The fix isn't force — it's heat. Run the heater for a few minutes to warm the installation compartment, and once the valve is above 7 °C it will close and hold. If you tour in the cold often, Truma's heating element accessory (part 70070-01) clips into the FrostControl and warms it to around 10 °C whenever the Combi is running, so you can fill up much sooner.

If you're storing rather than touring: during a frosty period the boiler must be drained. Switch off the power to the pump, open the hot taps, and open the safety/drain valve so the water container empties properly. Half-measures are how boilers get damaged.

The other winter job on a blown-air system is airflow. Cold weather is when you most want warm air reaching the extremities of the van — into the wardrobe, behind the seat bases, into the washroom. Blocked outlets and clogged filter pads are the usual culprits behind a van that heats the lounge beautifully and leaves the bed end damp.

4 Alde systems

Wet heating: the glycol is the whole game

An Alde system circulates a glycol-based heat transfer fluid through skirting radiators. It's beautifully quiet and very even — but the fluid is a consumable, and this is where owners lose money. The glycol doesn't just stop things freezing; it carries the corrosion inhibitors that protect the boiler and pipework. Those additives deplete over time whether you use the van or not.

Alde's guidance is clear: a standard ethylene glycol mixture should be changed every other year. Switch to Alde Premium Antifreeze and, under normal operating conditions, that interval extends to five years. Given what an Alde boiler costs to replace, a fluid change is one of the cheapest insurance policies in the van.

5 Managing moisture

Heat makes damp worse, not better

Here's the counter-intuitive bit. A warm van in a cold field produces a huge amount of condensation, because warm air holds far more moisture and then dumps it the instant it touches a cold window or a cold locker wall. Two people breathing overnight, a kettle, wet coats — it adds up fast.

Run the heating a little cooler and a little more constantly rather than blasting it and switching off. Crack a rooflight even when it feels wrong. And put moisture traps in the places warm air never reaches: under the front bunk, in the wardrobe, in the corner lockers.

One more thing worth carrying: a small gas cabinet heater as a backup. If your main system does go down on a cold night, having a second source of heat turns a trip-ending problem into an inconvenience. Just remember they need proper ventilation and they produce moisture as they burn.