GAS APPLIANCES AND THEIR USE

Propane gas, a form of liquid petroleum gas or LPG, is a safe fuel source used in most campervans and motorhomes for cooking and often for refrigeration and water heating. Please refer to the article in the June edition of The Wanderer for information on gas cylinders and as well as the reasons why you should not use autogas in motorhome appliances.

It is important that all gas appliances are installed correctly in accordance with Australian Standard AS5601 Gas Installation. Gas appliances used in motorhomes (with the exception of stoves) are to be a ‘room-sealed’ type that draws air for combustion from outside the vehicle and vents combustion gases to the outside.

Cooking with gas –
Ventilation - Because gas stoves are not ‘room-sealed’ appliances there must be permanent and unrestricted ventilation. Do not operate a gas stove in a pop-top campervan with the roof down.

The combustion of gas produces combustion products including carbon monoxide, but a stove operating properly produces relatively low levels that are dispersed through permanent vents usually built into roof rents and in the door. Extra ventilation can be provided by opening a window. The illegal use of autogas (propane/butane mix) can produce much higher levels of combustion products including carbon monoxide and there is unlikely to be sufficient ventilation to deal with this.

Flame failure cut-out - For quite a few years gas stoves have been available with a flame failure safety cut-out (a thermocouple) that only allows gas to flow while it senses heat from a flame. The thermocouple is a small ‘stalk’ immediately beside each burner. If the flame is blown out, the gas to that burner will be cut off when the thermocouple cools. When you light a gas burner that has a thermocouple you have to hold the knob down for several seconds until the device heats sufficiently to let the flow of gas continue. If the gas continually goes out immediately, or will only stay alight for a few seconds, it is likely the thermocouple is malfunctioning.

Stoves without thermocouples should only be used in a well-ventilated area, and greater care should be exercised. Camping stoves fuelled by gas canisters should only be used outdoors.

Safety when cooking -

• NEVER – EVER leave the kitchen area while cooking. If you are on hand a small problem can be attended to before it becomes a major incident.

• Never leave a heated pan of oil unattended.

• Never use pressure pack cans such as cooking spray or insecticide near a gas flame.

• Keep combustible materials such as curtains, tea towels and dishcloths well away from gas flames.

• Wear short or tight fitting sleeves and avoid reaching across the flames.

• Use a ‘long-nosed’ lighter for the stove rather than matches so your hand and sleeve are further from the flame.

• Position handles of saucepans inward to prevent them being knocked over.

• Use an exhaust fan or open a window to provide extra ventilation.

Dealing with a small fire -

• Install a fire extinguisher and a fire blanket near the stove. In the unlikely event of a fat fire on the stove, use the fire blanket or suitable extinguisher immediately and do not wait until a minor flare-up becomes a major event.

• Have someone call the fire brigade and turn off the gas at the cylinder if safe to do so.

• Remove anyone not actively involved in attending to the emergency (and any animals) from the motorhome.

• If you use a fire blanket, do not lift the edge to ‘see how the fire is going’. Fresh oxygen will cause the flames to flare up and this could result in facial burns to the person checking the fire.

• Do not allow yourself to be trapped. Stay between the fire and the door.

Heating – You will notice an appreciable warming of the living space when the stove is being used, however it should never be used to heat the room. Propane flames produce combustion products including water vapour and carbon monoxide and will quickly deplete the oxygen in the motorhome, particularly if the windows are closed to keep the room warm. The additional water vapour produced by the flames will add moisture to the atmosphere that is likely to condense on cold surfaces. It can result in mildew on soft furnishings and mattresses.

Under-floor and ducted gas heating systems similar to those used in USA and Europe are legal in Australia only if they draw air from outside and vent back outside. These systems must be fitted by a qualified gas fitter. If you have an imported fifth-wheeler or motorhome with a gas furnace heater, check that the appliance is approved for use in Australia.

Camping (catalytic) heaters powered by a propane or butane gas cylinder are dangerous and illegal in an enclosed space and they come with a clear warning that they can only be used in a well-ventilated location. Catalytic heaters can be dangerous indoors because they do not draw air from outside nor vent gases to outside and may produce unacceptably high levels of carbon monoxide that pollute the air in an enclosed living space. The gas is colourless and odourless and can prove fatal. If you are asleep there will be no warning – you simply won’t wake up.

If 240volt electricity is available, a simple electric fan heater is an inexpensive option. A more expensive, but totally safe way to heat a motorhome is to install a ‘room-sealed’ LPG or diesel-powered heater.

Gas leaks - Propane is heavier than air, and if released will pool in the lowest area. Consequently there is usually an air vent in the bottom of the door or the step well. For safety, a ‘rotting cabbage’ smell has been added to propane to help people detect a gas leak. Gas is not toxic but inhaling it will cause headache and nausea. It becomes dangerous when levels are sufficient to cause asphyxiation or if a spark ignites pooled gas and causes an explosion.

If you are concerned about the possibility of a gas leak indoors, you can install a gas detector wired into the 12volt electrical system. If you suspect there may be a leak, do not use a match or flame. Check the connection at the appliances, regulator and cylinders by spraying them with soapy water, and if there is a gas leak it will bubble. Clean the soapy water off afterwards.

If you smell gas:

• Extinguish any open flame.

• Turn off any appliance currently operating on gas such as the fridge or water heater.

• Shut off the valve on the gas cylinder.

• Don’t touch electrical switches.

• If the gas smell is inside the motorhome, open the windows.

• As a final safety measure, close the valve to all appliances connected to gas – cooktop, fridge and gas hot water system.

• Have a licensed gas fitter check the system before you turn the gas on at the cylinder.

Cylinders
How much gas is left? – If you have only one gas cylinder it is fairly important to know when it needs re-filling. Some cylinders have a gauge, but it may not be accurate. An inexpensive and accurate device to ‘measure’ the gas can be attached to the outside of the cylinder. This simple coloured strip changes colour to the level of the gas when hot water is poured over it. It is available from camping stores. When you pour hot water on the cylinder you may also find that a line of condensation will form indicating the level of gas remaining.

Re-filling cylinders - Cylinders are readily refilled at some service stations, large hardware stores and many caravan parks or you can exchange your empty cylinder for a full one. The design of all gas cylinders provides for an empty section at the top to allow the gas vapour to be withdrawn, not the liquid, and to allow space for the liquid to expand if it becomes heated. When you have a cylinder re-filled, the operator will usually add gas until it starts to vent, indicating the cylinder is filled to its designed limit (9kg in a 9kg cylinder). Exchange cylinders usually have 8.5kg of gas, even if the cylinder has a 9kg capacity.

If you use the exchange system, compare the expiry date and standard of surface finish (eg #2 or #4) on the replacement cylinder with your old one. Most exchange cylinders have a #4 quality surface finish, whereas most motorhomes are equipped with better quality #2 cylinders. (Refer last month’s Wanderer for more information.) A cylinder not larger than 9kg can be transported in a car for re-filling, but ensure it is secured in an upright position: do not let it tip over and roll around in the boot.

When a cylinder reaches its marked expiry date it cannot be refilled unless it is re-inspected and re-certified. One company quoted the cost as $20 and another quoted $35, both including replacement of the valve.

Changing a gas cylinder - With some gas installations you have to change the regulator from the empty cylinder to the full one, or you may have to swap the cylinders around. Close the valve on the empty cylinder before disconnecting it and do not open the valve on the new one until it is securely connected. Be aware that the connection on 4kg and 9kg cylinders has a left-hand tapered thread so you have to turn it clock-wise to loosen. A dual system is available where the change-over is simply a matter of turning a tap.

Safety when driving – Although it is legal to operate a fridge on gas while driving, it is unwise in a motorhome or campervan, particularly if the vehicle has a petrol motor. Petrol is more volatile than diesel, and there is a risk that petrol fumes will become ignited because of the fuel tank’s proximity to the fridge. Clause 6.2.6.3 of the Australian Standard: ‘Except for caravans fuelled by diesel, the minimum clearance between a fuel filler cap or fuel tank vent and an appliance flue or combustion air intake shall be 1m’. Note – ‘caravan’ means an RV.

It is advisable to shut off the valve on top of the gas cylinder before driving as a safety measure in case of a traffic accident. If you travel with a gas fridge operating, it should be turned off before entering a service station driveway in case there are residual fumes from a previous fuel spill. Gas must be turned off before boarding a vehicular ferry.

For additional practical information relating to motorhomes and campervans as well as travelling in general, refer to The Ultimate Travelling Companion.