Gas bottles for barbecues: connect, check and store safely

For garden gas barbecues, propane is predominantly used in Germany. Propane vaporises reliably even at low temperatures, so you can grill with it well into winter. Butane is common in small cartridges for camping and tabletop grills, but vaporises poorly in the cold – below about zero degrees, performance drops noticeably.

Which gas your grill can use is stated in the operating instructions and on the rating plate. Stick to it, because burners and nozzles are designed for a specific type of gas and a specific pressure.

The common sizes for barbecues are 5 kg and 11 kg. The 11 kg bottle is the standard for trolley grills, because it lasts a long time and is usually cheaper per kilogram. The 5 kg bottle is lighter and fits better into small cabinets or with compact grills.

With an exchange bottle (deposit bottle), you pay a one-off deposit and swap the empty bottle for a full one – at DIY stores, petrol stations or gas dealers, for example. Owned bottles belong to you, but must be inspected regularly and, at some dealers, are refilled rather than exchanged. For most hobby grillers, the exchange bottle is the less complicated solution.

The regulator reduces the high bottle pressure to the grill's operating pressure. In Germany, gas barbecues today are usually designed for 50 mbar. Older appliances or those bought abroad may be built for a different pressure – in that case the regulator must match the appliance exactly. A regulator with the wrong outlet pressure can lead to a weak or dangerously high flame.

Many regulators have a hose-break safety device that closes if gas suddenly escapes in large quantities. The hose should be approved for LPG, as short as possible and free of kinks, and must not touch hot parts of the grill. Rubber ages: if the hose becomes cracked, brittle or porous, it must be replaced immediately. Many manufacturers also specify a replacement interval.

Before you start: all burner knobs on the grill are set to "off", there's no open flame or ignition source nearby, and you're working outdoors.

You should check all connections after every bottle change and at the start of the season. Apply leak-detection spray or a mixture of water and washing-up liquid to the valve, regulator, hose connections and hose, then open the bottle valve. If bubbles form, gas is escaping.

In that case, close the bottle valve immediately, undo the connection, check the seal and reconnect. If it still leaks, the grill must not be used – the seal, hose or regulator then needs replacing. Never look for leaks with a lighter.

LPG is heavier than air. If it escapes, it collects on the ground and in hollows. That's why gas bottles must never be stored in cellars, garages with inspection pits or other rooms below ground level. Ideally they stand outdoors in a well-ventilated, shady spot, upright and secured against tipping over.

Protect bottles from strong sunlight and heat, keep them away from ignition sources and close the valve after every use. Spare bottles don't belong near a running grill, and you should only transport bottles in a car for short trips, upright, secured and with the interior well ventilated. In rented flats, the tenancy agreement or house rules may prohibit storing gas bottles on the balcony.

LPG has an odorant added so that you notice leaks. If you smell gas at the grill, close the bottle valve and all burner knobs immediately, put out any open flames and move away from the grill with anyone else nearby. Don't smoke and don't operate any electrical switches. Only once the gas has dispersed should you look for the cause with the soapy water test.

If a burner doesn't ignite straight away, turn the knob off again and wait a few minutes with the lid open before trying again. This lets unburnt gas disperse, which could otherwise ignite suddenly at the next attempt.

If gas ignites at a leaking point, close the bottle valve – if this can be done safely. In the event of a fire that can't be controlled, clear the area and call the fire brigade on 112 (the emergency number in Germany and across the EU).

After winter, a quick check is worthwhile: inspect the burner tubes for cobwebs and insect nests, as these can disrupt the gas flow and cause flashback. Check the hose for cracks, look at the seals and clean the grease tray. Then carry out the soapy water test and run the empty grill once on a high setting.

Small grills often run on cartridges instead of a bottle. There are various systems that aren't interchangeable: screw-in cartridges with a threaded valve, pierceable cartridges that are punctured when inserted, and cartridges with a click-in valve. Only use the type specified by the manufacturer, and only insert or remove cartridges outdoors and away from ignition sources. Take the cartridge out of the appliance after grilling if the instructions say so, and check the sealing rings on the connection regularly for cracks.

Empty cartridges don't belong in household waste; depending on your municipality, they're disposed of at a recycling centre or hazardous waste collection point – check with your local waste service. Never store full cartridges in the sun, in a hot car or near radiators.

If you travel abroad with your grill or motorhome, you'll quickly discover that bottle connections aren't standardised across Europe. In many countries, German regulators don't fit the bottles used there. Adapters exist for various countries, but they should only be used together with a suitable, approved regulator. Before you travel, find out which connection is common at your destination, or take enough of your own bottles with you, provided the transport rules allow it.

Finally, the most important points in brief, so you can quickly run through them before every barbecue.