What Is a Winterised Motorhome?

This is a topic that caused us a lot of confusion when we were looking for a suitable campervan for our motorhome skiing trips. We invested a lot of time in researching this and found some interesting and valuable information.

What Is a Winterised Motorhome? A winterised motorhome or campervan has the ability to retain all of its normal functions during usage in winter conditions.

Upon further investigation, we discovered that this is a complex topic and we feel it’s important for anyone looking to buy (*or rent) or upgrade a motorhome for their ski holidays to know what is important when it comes to winterisation.

NOTE: If you’re here to find out what steps you need to take to put your motorhome or campervan into storage over the winter, you are in the wrong place! This is a common misuse of the word winterisation which has come to be used by people looking to over-winter their recreational vehicles.

Winterisation Means Different Things to Different Manufacturers and People

If you are new to the motorhome game this might all seem very daunting – it certainly did to us when we first started out. So many terms that we weren’t familiar with and so much information to take on board. When it came to winterisation and what that meant, we very quickly discovered that it has a very simple definition but has no definitive standard that you as a potential owner or user can rely on.

We were fortunate – James is a plumber and his instant reaction to any claim about the workings of a water and heating system is to query it. We began by asking simple questions such as “is this motorhome winterised” and over a few months ended up grilling dealers about the robustness of the motorhomes they are selling.

What exactly makes this motorhome defy the laws of physics and defeat mother nature in an epic battle of wills?”

The results were definitive. Every manufacturer has a different definition and execution of ‘winterising’ their motorhomes and dealers are largely uninformed about what winterisation actually means to someone who intends on travelling in deep winter conditions.

motorhome ski

Let’s start by defining ‘deep winter conditions’.

Deep winter conditions, by our definition, in relation to motorhome skiing, are those you’d typically find between 1500m and 2000m and from the months of December to April in the Alps, Pyrenees and Dolomites. We can expect:

  • Fluctuations in temperature from +20°C to -20°C
  • Precipitation – lots of it in all states – rain, sleet and snow
  • High wind speeds and gusting
  • Treated roads – grit, salt and in some instances, synthetic anti-freeze chemicals

These are not the conditions for which the majority of winterised motorhomes are designed to withstand so it’s important that if motorhome skiing is something you really want to do, then investigating what level of winterisation you require can make or break your ambitions.

That said – it’s not difficult to establish and there are some awesome motorhomes out there for people looking for a truly winterised motorhome.

Thermal Insulation Grade Means Nothing

The first thing you can disregard during your research is Thermal Insulation Grading CE 1646-1 for motorhomes. Why? Because it’s tosh. We always wondered about this standard – one that each European motorhome manufacturer chooses to adhere to.

All our concerns about this standard were confirmed when we had the good fortune to interview two chief engineers from different motorhome heating manufacturers. We respectfully have chosen not to reveal these sources but can hand on heart tell you that in both off-the-record interviews, when specifically asked if the Thermal Insulation Grading had any scientific merit, both offered a categoric ‘no’ without hesitation.

This is not because there are no manufacturers that meet these standards – far from it. What it means is that every manufacturer can meet grade three specification because there is no standardised independent test that confirms a set list of criteria conducted under a specific methodology. It is all very ambiguous and to top it all off – it’s a self-certification. In layman’s terms this means that someone within each manufacturing business signs-off the motorhome design to say it meets these standards. This makes the certification irrelevant as a benchmark.

It’s also important to share that this testing is not on the heating systems themselves. The grading is on the motorhome and not the components. That means that a heating system that might fail in one motorhome, may operate perfectly in another.

So, What Are We Looking for in a Winterised Motorhome?

In order to function well in deep winter conditions, we need to consider the following:

Water – Tanks, Pipes and Taps


Whether you are buying new or used, you should hold out for a van that has a double floor where at least the fresh water tank is housed inside the vehicle. This reduces the chances of losing your water supply, which as anyone who has experienced this, is a pain in the backside.

This also says a lot about the rest of the vehicle. Any vehicle where the manufacturer has proactively designed tanks internally, is considering colder conditions in general which is reassuring to know.

If your waste water tank is externally seated, you should check the degree to which it is insulated and consider giving that a boost with some better or new insulation and don’t forget to consider your ‘service installations’ which refers to the pipes and connectors. It’s also very easy to fit after-market tank heaters of which there are two types – the probe type that sits inside the tank and the external type which is a blanket wrapped around the tank.

Some tanks also have heated elements in them to prevent freezing as standard – it’s important to note this never completely prevents freezing, it simply slows down the process which means that in ordinary conditions, your tanks are unlikely to freeze. We however experienced some fairly unusual conditions and once experienced water freezing on contact as we filled the tank – even with a heated element installed! Some battles you will never win!


Pipes are the most common sticking points when it comes to freezing up your system so it’s important to pay close attention to the insulation your van has on all pipes.

Firstly – a winterised motorhome should have high grade insulation on all pipes that are at risk. In a van with a double skinned floor, which has heating directly concentrated in this area, it is probably over-kill to see pipe insulation here. However, in a motorhome where the tanks are internally located under seats for example, there are some areas where the pipes might be flush with the exterior walls so we like to see insulation here – something you can retro fit if you have concerns.

All external pipes (including waste pipes) will have high grade pipe insulation on a winterised van. This needs to be snug with no gaps, particularly around fittings. It’s also important to check that pipes are all flowing in the right direction! This means that all water can escape, leaving nothing resting in u-bends to freeze and expand causing blockages.

Day 2 of our first motorhome ski adventure. A small freeze turns into a huge re-plumb of the entire habitation area in a brand new motorhome (see beds still covered with protective plastic).


In a winterised motorhome, the waste outlet valves should have a minimum bore (internal diameter) of 1” so that any water coming out of your grey tank is not impeded by a value with a smaller bore size than the pipe diameter leaving your sinks and shower. This simply means that there are no road blocks where water can start misbehaving.

Heating and Climate Control

This shouldn’t be significantly different in a winterised motorhome but we would expect to see some attention to the under floor area and the garage (your winterised motorhome really should have a garage of some sort). This might be by way of blown air either through a convention fan from a wet system (Alde and Truma) or a simple duct from a blown air system (Whale, Eberspacher etc). The purpose of this is not only to prevent the system freezing but also to minimise condensation forming in these unseen spaces. This is particularly important where you drying your wet ski kit in the garage area which can become susceptible to mould growth. Wet systems should also be primed with anti-freeze.


This is something that’s largely taken for granted and certainly should be in a new vehicle. However, the majority of people reading this are probably investing in a used motorhome or campervan or are converting one themselves. This means mechanics are an important thing to winterise too.

If you’re about to drag your used motorhome or campervan into the mountains for the first time, it’s good to give it the best chance of success! That means a full service, with drain and change of all relevant lubricants and fluids.

Lubricants and Fluids – make sure your motorhome has good quality oil in the engine and anti-freeze where anti-freeze is necessary. A really good quality screen wash is essential and will save you hours of sitting about waiting for the tank and pipes servicing your windscreen to defrost. After testing over 25 different brands and types, we recommend the Autoglym Ultimate Screenwash which is tested to -45°c (we have never had an issue down to -25°c). You can find out why we don’t use anything else here.

Check your hand brake cable– You should make sure the tension is correct and that there is no corrosion along the length of the handbrake cable.

Door seals– It’s a good idea to spray or rub your door and window seals with silicon grease lubricant. This stops them getting brittle and reduces the chances of your doors getting frozen shut. You don’t need an expensive version.

Door handle and locking mechanisms– in our experience, even the fanciest motorhomes have some areas that we feel are weak points and the habitation door seems to be one of these. A motorhome that is up to withstanding deep winter conditions needs a robust habitation door handle and locking system. You’ll find your door gets considerably more use than when you’re summer touring and a flimsy plastic mechanism will suffer. Do not underestimate how debilitating being unable to lock your door is – at least one of us was trapped in our motorhome for 6 days over New Year whilst we waited for a replacement door handle and lock – unable to leave together as this would have invalidated our insurance and sleeping with one eye open with no method of securing ourselves inside the vehicle. Look for a sturdy handle and lock and consider using the old fashioned WD40 method to lubricate the locks before you depart.

Vehicle Body Insulation

As far as we can decipher, there is no special construction used by mass manufacturers specifically for winterised motorhomes and campervans. Each manufacturer has their own trademarked design which meets their own technical specification.

If you are looking to convert a vehicle yourself or engage a conversion specialist, you have far more scope for maximising the insulation properties by using methods and materials that match each area specifically and are not necessarily suitable for mass production methods.

Additional Winterising Equipment and Tips

If you are confident you have a well winterised base motorhome or campervan, what else do you need? We don’t consider a van winterised until it has the following essential kit on board:

  • Winter or all-season tyres
  • A good quality external thermal insulation screen and bonnet cover
  • Rubber door mat
  • High tog duvet
  • Neoprene or rubber kneeler

(Here’s a bunch of stuff we rate)

Related Questions

Can you use a motorhome in the winter? Yes – you can use any motorhome in winter conditions – whether all the systems will work is a different matter!

What’s the best motorhome for winter use? The general consensus is that European motorhome manufacturers construct their vehicles to a much higher standard in terms of winterisation than their UK counterparts. The German and Slovenian brands have the best reputation for this.

What’s the best insulation for a motorhome? This depends on a great many factors but a combination of insulating fabrics, foam and rigid expanded foams is how you expect to achieve the greatest level of all round thermal insulation.

*If you’re thinking of hiring a motorhome for your ski trip, here are a few things you should know before you go.


Gobby, opinionated, professional ski bum. Co-founder of the Winterised Project.

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