Motorhome Gas: What Fuel Type Should You Use?

The most important thing to note about motorhome gas is a fact that one of our electrical experts quotes on a regular basis and that’s the amount of energy stored in a motorhome gas bottle in comparison to a battery.
 

Like for like, one 6kg motorhome gas bottle holds the same amount of energy as 42 leisure batteries. So, gas is a good thing for motorhomes, where space and weight is at a premium.
 

What does motorhome gas do?

As already mentioned, gas is fitted in motorhomes to power the cooking, the heating/hot water and the fridge. It’s very efficient in all respects, but it does add a layer of complexity with its system and servicing requirements.

How does motorhome gas work?

All motorhome gas systems work the same way: there’s a bulk storage container of some sort with a regulator. This feeds gas into the pipework that then runs to all the appliances that need it.

The refilling is where systems differ as there are two types of system. The most common is the exchange cylinder – such as the most well-known, Calor. You simply remove the empty gas bottle and swap for a new one.

The refillable gas systems for motorhomes involve an underslung tank or a special type of cylinder installed in an existing gas locker and this is topped up at LPG stations around the country.

There are two main types of gas – butane and propane. 

We have found that some websites state butane is cheaper than propane and doing an online search showed that in some places this seems to be true and in others it is not the case.

Propane (C3H8) is probably the most widely used gas and one of many gases that make up generic LPG. However, Propane itself is a byproduct of the processing of natural gas as well as crude oil refinery. 

It is odourless and when in the cylinder under pressure is a liquid, but converts back into gas within the system.

Pros:

• Propane can be used in lower temperatures
• Better for multiple appliances at once

Con:

• Needs odour adding in for safety

Butane (C4H10) has a smell similar to natural gas and comes from crude oil processing. For those looking to impress friends, it appears as two isomers – n-butane and isobutane.

Pro:

• Reported to be slightly cheaper

Cons:

• Butane doesn’t work so well in colder temperatures, producing less gas below 4˚C
• Comes in smaller cylinders commonly

The other thing is that butane, in the form of Campingaz cylinders, can be exchanged across Europe. The biggest gas brand in the UK, Calor, is only available in the UK, as is Flogas, one of the other main suppliers. 

Butane and different European gas bottles (from Cepsa, etc) will require different regulators to work.

While still in early days, renewable liquid gas has been suggested as an alternative to the current systems. 

While electrical heating and the like can work in brick built homes, the system complexity, size of units and high demands on the grid make it untenable for leisure vehicles. 

According to Liquid Gas UK, the industry body for LPG, “two forms of renewable liquid gases (RLGs) emerge as promising solutions for the caravanning sector: bioLPG and renewable dimethyl-ether (rDME).”

It says that, ”BioLPG and rDME are chemically identical to LPG and are considered a ‘drop-in’ solution made from a diverse mix of sustainable biological feedstocks and processes, including domestic or agricultural waste, energy crops, or recycled carbon.”

It seems that this is available in domestic settings, but has not yet filtered into the leisure vehicle market, although watch this space.

The second debate is about fitted gas tanks verses exchange cylinders and even user-refillable cylinders. There’s a few key points to highlight:

Exchange cylinders, from the likes of Calor, Campingaz and Flogas are possibly the most convenient, with numerous locations to swap your empty cylinders for full ones around the UK – garden centres, builders merchants, caravan dealers and even campsites.

However, the costs can be higher, particularly if you only have space for smaller cylinders and are heavy gas users. Also, if you plan to travel abroad, then you’ll have to do your gas usage calculations as the main exchange cylinder suppliers only operate in the UK. Campingaz is available all over Europe, but not in the same cylinder sizes and they can work out much more expensive in the long run.

The second option, which may reduce the cost of gas, is a refillable cylinder system. This uses your existing gas locker and set-up but swapping out for cylinders that can be refilled at LPG fuel points across the UK. The system needs a shut-off mechanism that only allows the cylinder to be filled to 80% (this leaves space for LPG to convert to gas vapour before it is drawn through the gas pipes).

Make sure you have a remote fill point mounted on the outside of the vehicle – you are less likely to encounter resistance from forecourt staff – refilling cylinders on the forecourt is often not allowed because of a lack of understanding about the specifics of refillable systems in motorhomes.

Underslung tanks resolve the storage issues, if you have space for a tank, and people do talk about the lower cost of LPG at fuel stations, but factor in the installation and you’ll have to refill a huge number of times before you break even.

Also, with refillable LPG, there is a concern about the availability of LPG at fuel pumps in the UK. One of the biggest fuel station operators, MFG, has stated that it will withdraw LPG from all its forecourts by 2024. It’s primarily due to the move away from gas-driven vehicles towards electric ones.

That’s not to say there are not still options. There are other independent operators and some of the big oil companies' stations will continue to offer Autogas; however, the only one that seemed to have a filter for this on its forecourt finder was BP.

One of the refillable gas system manufacturers, Gaslow, has a useful search function on its website with some tips for finding a place to refill your LPG cylinder. 

And, Marquis installed refilling points at three of its branches, Durham, Exeter and Surrey. As this is an attendant only service, a member of staff will top up your tank or refillable cylinder for you. https://www.marquisleisure.co.uk/lpg-gas

It’s also worth bearing in mind the ferry company and LeShuttle guidelines on LPG systems if you plan to travel to Europe. Most will have maximum amounts of gas and will require the system to be shut off while on board.

LeShuttle has a useful advice page listing its terms, while P&O guidelines can be found in its prohibited items page and Brittany Ferries lists this on its FAQs section

As with anything, gas systems can become dangerous if neglected or treated carelessly. DIYers should not tackle gas-related maintenance or servicing unless trained and if you do carry out any work, always get it checked by an accredited leisure vehicle technician that holds qualifications specifically for leisure vehicle LPG systems.

1. Get the gas system checked annually – this often involves leak detection as well as a check of the regulator, hose, pipe and manifold. The technician will check that gas is being delivered to all appliances and check the retaining straps or holders in the gas locker are working. They will also check that the gas drops are clear – if you do tend to use the gas locker for storage, make sure nothing obscures these vents. There are over 550 service centres (including mobile technicians) listed on the Approved Workshop Scheme (run by the National Caravan Council – NCC), with minimum training standards. It’s worth bearing in mind that if you plan to hire out your motorhome, your gas system will need to have an up-to-date Landlord Gas Safety Record.
2. Check gas hoses. If you’ve bought a used motorhome, it might be worth checking the age of the hoses in the gas locker. These do deteriorate with age and will have a date on them, as will most of the other elements of the gas system.
3. Inspect cylinders. Cylinders need to be checked and renewed every 10 years – the same goes for regulators too. With exchange cylinders this is all handled within the normal return process; however, if your motorhome has a fixed cylinder or an underslung tank then this should also be checked regularly. Also, these should be recertified or replaced every 10 years – Gaslow has a swap scheme for such cylinders and tells its users that the cost of recertification can outweigh the cost of a new cylinder under its replacement scheme.

Also, it’s worth knowing that while LPG is odourless, the industry adds a smell agent to help detection. However, all gas appliances (hob, fridge and heaters) can give off carbon monoxide and this is undetectable by smell, sight or taste. So make sure a carbon monoxide detector is fitted and that it has been checked – the sensors in these devices do need replacing every 7-10 years. Insurance company, Lifesure, has some really useful advice on carbon monoxide in motorhomes.

There are many gas-related questions, with possible answers on our forums. This covers everything from problems with hobs and fridges to underslung tank life, getting gas abroad and more. Browse and read as a guest or register for free to post your own question of help other motorhomers in need by providing your experiences.