Paraffin or Bottled Gas Heaters: Safe Use, Storage and Refuelling

A paraffin heater and a bottled gas heater do the same job in different ways: both burn fuel in the room you are sitting in, and both need air and a clear escape route for fumes. Neither is a set-and-forget appliance. If you are choosing between them, the first thing to understand is that the fuel is not the main risk. The main risk is carbon monoxide, an invisible gas produced when any fuel burns without enough air, and the second is fire from a hot surface close to furniture, curtains or washing.

The practical rules are the same for both. Only use a heater in a well-ventilated room, keep a window slightly open, and never sleep in a room with an unflued paraffin heater or gas fire¹. Fit a carbon monoxide alarm in every room that contains a gas or paraffin heater². Keep at least 1 metre (3 feet) between a gas space heater and anything flammable³. Store fuel and cylinders outside the home, and change cylinders outdoors or in a well-ventilated space⁴.

Bottled gas heaters run on liquefied petroleum gas (LPG), such as butane or propane, and heat a room quickly, but you have to change the cylinders, which is a hassle and carries fire risk⁶. Paraffin heaters are a major cause of condensation, and every gallon of paraffin burnt produces 10 pints of water⁷. Both are an expensive way to heat rooms⁷. If you have mains electricity, an electric heater avoids the fuel and fume problems entirely; see our comparison of electric or gas portable heaters.

Paraffin or bottled gas: how each heater behaves

A portable gas heater uses LPG, either butane or propane, and can be moved anywhere in the room. It heats the space it is in quickly, but it requires you to change the gas cylinders, which can be a hassle and also poses fire risks¹⁰. The fuel comes in refillable cylinders, and the heater itself is usually a radiant or convector unit that sits on the floor. Because it burns gas in the room, it needs a steady supply of fresh air and a carbon monoxide alarm nearby.

A paraffin heater burns liquid paraffin, drawn up through a wick, and gives out a steady, gentle heat. It is quieter than a gas heater and needs no cylinder changes, but it must stand level, preferably on a non-combustible base, and away from draughts before you light it⁷. Paraffin is bought in containers and poured into the heater's tank, so refuelling is a routine job that has to be done outside.

Both types are an expensive way to heat rooms compared with mains gas or electricity⁷. That matters when you are deciding how much fuel to keep: a heater that is costly to run is best treated as a backup for one room during an outage, not as a way to heat a whole house through winter. For the wider picture of keeping warm without mains power, see Heating and Cooking Without Mains Power or Gas.

Some homes cannot use either. Highland Council tenants, for example, are told never to use paraffin or bottled gas heaters because they are not allowed in council homes¹². If you rent, check your tenancy agreement before buying either type.

Carbon monoxide: the risk both heaters share

Carbon monoxide is produced when fuel burns without enough air, and it can kill. The risk rises in winter, when people use fuel-burning appliances such as gas heaters and boilers more¹³. Cold weather also pushes people towards malfunctioning or inappropriate appliances to heat their homes, which can increase the risk of carbon monoxide poisoning¹⁴. Using a gas cooker or oven to heat a room is one example: it is inefficient and could put you at risk of carbon monoxide poisoning¹⁵.

Gas heaters must only be used in well-ventilated areas, otherwise you could be at risk of carbon monoxide poisoning⁶. Using gas heaters carries that risk, so you should have a carbon monoxide alarm in the same room¹⁰. The same applies to paraffin: fit a carbon monoxide alarm in all rooms containing solid fuel, gas or paraffin heaters². Fire services also recommend an alarm in rooms with a fixed combustion appliance such as a gas fire, gas boiler, log burner or open fireplace¹⁶.

If you have a portable gas heater that uses gas bottles and is approved for indoor use, make sure the room is well ventilated and follow all the instructions carefully, because the fumes can be dangerous¹⁹. If a heater is not approved for indoor use, do not bring it inside at all: never use outdoor heaters such as propane or kerosene indoors unless they are specifically approved for indoor use³.

Ventilation: keep air coming in while the heater runs

Every fuel-burning heater needs air, and a modern draught-proofed home can be too tight for one. Only use gas or paraffin heaters in well-ventilated areas, because you could suffocate if the room is not properly aired⁸. Keep a window slightly open to improve ventilation and reduce the build-up of condensation and damp¹¹. Make sure rooms are well ventilated and do not block air vents; if your home is double-glazed or draught-proofed, ensure enough air circulates for the heaters in the room¹.

Ventilation is not just about fumes. LPG and paraffin heaters are a major cause of condensation, so be sure the window is open a little, and remember that every gallon of paraffin burnt produces 10 pints of water⁷. That moisture has to go somewhere. If it condenses on cold walls and windows, you get damp, and damp makes a cold home colder. A slightly open window is the simplest fix, and it costs less heat than people fear because the heater is replacing it continuously.

When you change a gas cylinder, ventilation matters even more. Try to do it in the open air; otherwise, open windows and doors to increase ventilation²⁰. Gas heater cylinders should be changed in the open air, and if you have to change them indoors, make sure all rooms are ventilated and open windows and doors². Never change a cylinder on a stairway or other escape route⁷.

Where an indoor heater must never go

The bedroom is the first exclusion. Portable gas heaters must not be used in bedrooms and should only be used in well-ventilated rooms⁴. Do not sleep in a room that has an unflued gas fire or a paraffin heater¹. The Health and Safety Executive sets limits for gas appliances in rooms converted to sleeping accommodation: since 31 October 1998, such a room should not contain a gas fire, gas space heater or gas water heater over 14 kilowatts gross input unless it is room sealed, and appliances of 14 kilowatts or less must be room sealed or have an atmosphere-sensing device²¹. Those rules are about fixed appliances, but they show why sleeping rooms are treated differently.

Bathrooms and shower rooms are out too. Standard portable heaters, gas and electric, must not be used in shower or bathroom areas⁴. Basements and other enclosed areas are unsuitable for fuel-burning heaters because fumes collect; fire services advise against using diesel space heaters in bedrooms, basements or other enclosed areas³.

Tents, caravans and cabins have their own rules. Never take a gas stove, light or heater into a tent, caravan or cabin unless it is a permanent fixture, installed and maintained correctly¹⁸. Never use barbecues or gas stoves inside tents, awnings, caravans or mobile homes, because this poses a serious carbon monoxide risk as well as a fire risk¹⁸. In a caravan or mobile home, make sure heaters work properly, use a Gas Safe engineer to check or fix gas heaters, and never dry clothes on or right next to the heater²². For more on this, see Keeping Warm and Cooking in Tents and Caravans.

Storing paraffin and gas cylinders safely at home

Store gas, paraffin and LPG cylinders safely outside the home and out of direct sunlight, and not on balconies⁴. Store fuel in approved containers and keep it away from heat sources; store fuel outside the home where possible and keep quantities to a minimum¹¹. For gas heaters, store cylinders outside and away from direct sunlight and frost, and do not store more gas cylinders than you need⁶.

Paraffin has a specific limit. Keep spare fuel outside the home: no more than 23 litres (5 gallons), and preferably only 9 litres (2 gallons), should be kept, in purpose-made containers stored away from sources of heat⁹. That is a legal-style limit worth respecting, not a target to reach. Buy only what you will use in a season, and keep the container sealed and labelled.

Never buy a second-hand paraffin heater, as they can be dangerous⁹. A used heater may have a damaged wick, a leaking tank or a rusted body that you cannot see, and the saving is not worth the risk. For more detail, see Where to Store Gas Cylinders at Home.

Refuelling and changing cylinders without fire risk

Refuelling is the moment when fuel vapour is most likely to be in the air, so do it outside. Maintain ventilation when using kerosene heaters to avoid a build-up of toxic fumes, and always refuel outside²⁴. Before lighting a paraffin heater, ensure it is standing level, preferably on a non-combustible base, and away from draughts⁷. Let the heater cool before refilling it, and never fill it while it is lit.

For a gas heater, change the cylinder in a well-ventilated place and away from sources of heat and ignition⁴. Try to do it in the open air; if you must do it indoors, open windows and doors to increase ventilation²⁰. Never change a cylinder on a stairway or other escape route⁷. Check that connections are secure and undamaged before use, and check gas and electrical equipment such as hobs, heaters and gas bottles before use¹⁸.

If you smell gas at any point, stop. Open doors and windows, avoid using naked flames, and do not smoke or strike matches²⁵. Extinguish all naked flames, do not smoke or strike matches, and call the gas emergency service; immediate access will be required²⁶. If the smell is paraffin rather than gas, stop using the heater, ventilate the room and have it checked before you light it again.

Signs of a fault and what to do straight away

A gas appliance that is burning badly gives warnings. Lazy yellow flames instead of crisp blue ones, black marks or stains on or around the appliance, and lots of condensation in the room are all signs of a fault¹⁶. If you see any of these, stop using the heater, ventilate the room and have it checked by a Gas Safe Register engineer¹⁶. The same engineer can check or fix gas heaters in caravans and mobile homes²².

For a paraffin heater, watch for a smoky flame, a smell of fuel, a leaking tank or a wick that will not stay alight. A strong or persistent smell indoors is a reason to stop using it and have it looked at. Never ignore fuel odours or visible smoke or fumes³.

If you smell gas, treat it as an emergency: open doors and windows, avoid naked flames, do not smoke or strike matches, and call the gas emergency number²⁵. If you have a carbon monoxide alarm, fit it in every room with a fuel-burning heater and test it regularly²⁷. For the wider picture of gas and heating failures, see Gas and Heating Failures.

Where to get help: gas emergencies, fire safety visits and alarms

For a gas appliance, get your heater checked by the Gas Safe Register¹⁶. Use a Gas Safe engineer to check or fix gas heaters, including in caravans and mobile homes²². If you smell gas, open doors and windows, avoid naked flames, and call the gas emergency service; immediate access will be required²⁵.

Fire and rescue services offer home fire safety visits and advice, and many will fit or advise on smoke and carbon monoxide alarms. Contact your local fire and rescue service for a home safety check, and ask about carbon monoxide alarms if you use any fuel-burning heater². If you are a carer or support someone who is, fire services publish specific guidance on keeping the person you care for safe²⁸.

For help keeping warm, see Warm Spaces and Warm Hubs and Extra Help in an Emergency. If you are on a low income or have a health condition, ask your council about the Priority Services Register and cold weather support. For the full picture of preparing your home for winter, see our Before-Winter Checklist for Your Heating and Stove.