Gas heater guide: choosing the best gas heater in SA

A gas heater is one of the most popular ways to stay warm in a South African winter, because it gives instant heat and keeps working through load shedding. The best gas heater for you depends on the size of the room, how well it’s ventilated and whether you want to warm the people in front of it or the whole space. This guide compares the types, explains sizing and running costs, and covers the safety features you should never compromise on.

The short answer

• For quick, direct warmth in a lounge or open-plan room: a radiant (infrared panel) cabinet heater on wheels with a 9 kg cylinder inside.
• For gentler, more even heat in a well-ventilated room: a blue flame (convection) heater.
• For low, steady background heat: a catalytic heater.
• For a stoep, patio or outdoor entertainment area: an outdoor patio heater, and only outdoors.
• Whatever you choose: insist on an oxygen depletion sensor (ODS), a flame-failure device and, ideally, a tip-over switch, and never run it while you sleep.

Gas heater types compared

Radiant (infrared panel) heaters

The classic South African gas heater is a cabinet on wheels with one, two or three ceramic panels and a 9 kg cylinder in the back. Each panel you light adds heat, so you can turn it down on a mild Durban evening and up on a frosty Highveld night. Radiant heat warms you and the furniture rather than the air, so you feel it almost immediately, but the warmth fades with distance.

Blue flame (convection) heaters

Blue flame heaters warm the air, which then circulates. That gives a more even temperature in an enclosed space, but it takes longer to feel warm and the heat escapes quickly through open doors.

Catalytic heaters

A catalytic heater produces heat through a chemical reaction on a pad rather than a visible flame. They’re quiet and give steady, low-level heat, but they still consume oxygen and need ventilation and an ODS: “flameless” doesn’t mean “fume-free”.

Gas heaters vs patio heaters

Patio heaters are designed for open air, where wind carries away combustion gases, and put out far more heat than a closed room can safely handle. Never use an outdoor or patio heater indoors, in a garage or in an enclosed braai room. See our patio heater guide for outdoor options.

Sizing a gas heater for your room

Gas heaters are rated in kilowatts (kW). A higher rating gives more heat, but also burns more gas and uses more oxygen, so bigger isn’t automatically better.

1. Measure the room. Work out the floor area (length × width) and, if your ceilings are high, the volume (length × width × height). Manufacturers usually state either a maximum heating area or a minimum room volume.
2. Check the manufacturer’s minimum room size. Indoor gas heaters need a minimum room volume to operate safely. If the room is smaller than that, the heater isn’t suitable, no matter how cold it is.
3. Think about your climate and house. A Highveld home with single glazing, a tiled floor and high ceilings loses heat far faster than a well-insulated coastal flat. Choose a heater with adjustable settings so you can run it on low most of the time.
4. Use the settings. A three-panel heater on one or two panels is often enough once the room has warmed up.

If you want to heat several rooms or the whole house, a portable gas heater isn’t the right tool. Look at a closed combustion fireplace or a flued gas fireplace instead.

Safety features to insist on

Every indoor gas heater burns oxygen and produces combustion gases, including water vapour, carbon dioxide and, if anything goes wrong, carbon monoxide (CO). These features are your first line of defence:

• Oxygen depletion sensor (ODS): shuts off the gas if the oxygen level in the room drops. Don’t buy an indoor gas heater without one.
• Flame-failure device: cuts the gas if the flame or pilot goes out, so unburnt gas isn’t released into the room.
• Tip-over (anti-tilt) switch: shuts the heater off if it’s knocked over. Some models have this and some don’t, so check the specification before you buy.
• Piezo ignition: lights the heater with a button, so there are no matches near the gas.
• A sturdy guard and stable base: important with children and pets.
• A proper regulator and hose: use the regulator and hose specified for your heater and cylinder, and replace hoses that are cracked, stiff or past their date.

Safety features are a backstop, not a licence to close up the room. Read our full gas heater safety guide before winter, and fit a carbon monoxide alarm in any room where you use gas (see smoke and CO detectors).

The non-negotiables

• Keep a window or door slightly open while the heater is on.
• Never leave a gas heater on while you sleep, and never use one in a bedroom, bathroom or small closed room.
• Keep it at least a metre from curtains, couches, washing and anything else that can burn, unless the manual gives a larger distance.
• Do a soapy-water leak test every time you connect a cylinder.
• Switch off at the cylinder valve when you’re done, not just at the heater.

Cylinders: 9 kg, 19 kg or 48 kg?

Most portable cabinet heaters are designed to take a 9 kg LPG cylinder inside the cabinet. That’s the size you’ll swap or refill most often. Larger 19 kg and 48 kg cylinders are used for fixed installations such as gas fireplaces, hobs and geysers, where the cylinder stands outside and gas is piped into the house. Don’t try to run a cabinet heater from a big cylinder standing next to it indoors. There are limits on how much LPG you may keep inside a home (the LP Gas industry has cited 9 kg for a flat and 19 kg for a house), and 48 kg cylinders belong outside. If you’re unsure, ask a registered gas installer.

Cylinder basics:

• Keep cylinders upright, and store spares outside in a shaded, ventilated spot, never in a cupboard or below ground level, as LPG is heavier than air and pools in low places.
• Buy refills or exchanges from reputable LPG dealers and filling stations.
• Check the valve and the cylinder’s condition when you swap. Don’t accept a rusted, dented or damaged cylinder.

Running costs: how to work them out

There’s no single cost figure, because LPG prices change and vary by region and dealer. You can work it out yourself in two steps.

1. Find the gas consumption. Look in the manual or on the rating plate for the consumption in grams or kilograms per hour (g/h or kg/h) at each setting. If you only have the kW rating, you can estimate: LPG contains roughly 13 to 14 kWh of energy per kg, so a heater burning at 4 kW uses roughly 0.3 kg per hour on full.

2. Multiply by your gas price.

Cost per hour = consumption (kg/h) × price per kg

To get the price per kg, divide what you pay for a refill by the cylinder size. For example, divide the price of a 9 kg refill by 9.

From there you can estimate how long a cylinder lasts: a 9 kg cylinder divided by 0.3 kg/h gives around 30 hours on full, and longer on lower settings.

To compare with electricity, use the same logic: a 2 kW electric heater uses 2 kWh per hour, so cost per hour = kW × your tariff in rand per kWh (from your Eskom or municipal bill). Our oil heater vs gas heater guide walks through the comparison, including load shedding.

Brands sold in South Africa

Indoor and outdoor gas heaters from brands including Alva, Cadac, Goldair and Megamaster are sold locally, alongside many house-brand and unbranded models. Ranges change every winter, so compare the specific model’s safety features, kW rating and minimum room size rather than relying on the brand name alone.

You’ll find gas heaters at hardware chains, home improvement stores, big-box retailers, outdoor and camping stores, gas dealers and online marketplaces. Price bands are roughly:

• Entry: single-panel or cylinder-top heaters, basic cabinet heaters. Check carefully that an ODS and flame-failure device are included.
• Mid: three-panel radiant or blue flame cabinet heaters with ODS, flame failure, piezo ignition and often a tip-over switch.
• Premium: flued gas heaters and gas fireplaces, which need professional installation.

Installation: portable vs fixed

A portable cabinet heater with a 9 kg cylinder inside is a plug-and-play appliance. Connect the regulator by hand as the manual describes, leak test, and you’re done.

A fixed installation is different. If gas is piped from cylinders outside into a heater or fireplace, the work must be done by a gas installer registered with SAQCC Gas, who issues a Certificate of Conformity (CoC) when the job is done. Insurers can refuse claims for gas installations without one, and you’ll need a valid CoC when you sell the house. Read our gas compliance certificate guide, or get quotes from registered gas installers.

Care and maintenance

• Before winter: check the hose and regulator for cracks or perishing, dust the panels gently, and do a leak test.
• Watch the flame. A lazy, yellow or sooty flame, a strong smell or soot marks above the heater mean something is wrong: switch it off and have it serviced.
• If the ODS keeps tripping, the room needs more fresh air or the heater needs attention. Don’t bypass it.
• Off-season: disconnect the cylinder and store the heater upright somewhere dry.

FAQ

Are indoor gas heaters safe?

They can be, when you use a heater rated for indoor use with an ODS and flame-failure device, keep the room ventilated, keep it away from anything flammable and never leave it on while you sleep. Fitting a carbon monoxide alarm adds an important extra layer.

How long does a 9 kg gas cylinder last in a heater?

It depends on the heater’s consumption and the setting you use. Divide 9 kg by the consumption in kg per hour from the manual. A heater using about 0.3 kg per hour on full will run for roughly 30 hours, and longer on lower settings.

Can I use a gas heater during load shedding?

Yes. Portable gas heaters don’t need electricity, which is one of their biggest advantages. Just remember the usual rules: ventilation, no sleeping with it on, and a leak test after every cylinder change.

Can I use a patio heater inside?

No. Patio heaters are made for open-air use only. Indoors they can quickly use up oxygen and build up carbon monoxide, and their heat output is a fire risk in an enclosed space.

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