What should you do if your aircon smells like burning?

Aircon burning smell: switch off at the isolator

Work through these steps in order.

1. Switch off at the remote. Stop the aircon with the remote control as soon as you notice the smell.
2. Turn off the isolator or breaker. If the aircon's isolator switch or its breaker is dry and safe to reach, turn it off. Leave it alone if it is wet, near water, sparking or smoking, or if your hands or the floor are wet.
3. Keep people away and open windows. Keep children and pets out and open the windows.
4. Call for help. Call an aircon technician for a fault in the unit, or an electrician if the smell seems to come from the isolator, a socket or the distribution board (DB box).

Daikin's air conditioner troubleshooting page gives the same order for a burnt odour: stop operation, unplug the power cord or turn off the circuit breaker, and contact the place of purchase. It is a global page, so follow your own model's manual too.

For a smell at the isolator or a socket outside office hours, compare 24-hour electricians.

Dust smell or electrical fault?

Daikin Singapore suggests a simple first check: switch the aircon off. If the smell goes away, the aircon was the source. If the aircon has not been used for a long time, settled dust can cause a burning smell when it is turned on, and a smell that is only temporary and goes away quickly is nothing to worry about. If you use the aircon regularly and still smell burning, Daikin says it might be an electrical malfunction in the power wires, compressor, fan or circuit board. If the smell persists, turn the aircon off right away and get a professional.

If your aircon smells like burning plastic rather than dust, timing still matters most: a smell that persists, or appears during regular use, means keeping the unit off until a professional has checked it.

Other smells point to other problems. Daikin Singapore links a smell like exhaust fumes to a possible leak in the refrigerant line, and a stale, dank smell most often to mould from water in the drain pan, drip lines or ducts.

Who to call: aircon technician or LEW

A fault inside the aircon, such as a problem with the fan, compressor or circuit board, is a job for an aircon technician; compare companies for aircon repair.

A burning smell at the isolator, a socket or the DB box is electrical work. The Energy Market Authority (EMA) says electrical work at home should be carried out or supervised by an LEW, and lists replacing switches and socket-outlets and repairing or replacing circuit breakers among that work. EMA says electrical work in an HDB flat needs a Licensed Electrician, the class of LEW approved for loads of up to 45kVA. If the smell is at a socket, read our guide to a burning smell from a socket.

The Consumer Product Safety Office (CPSO) advises having qualified service personnel inspect an appliance you suspect is malfunctioning.

Preventing it

• Clean the filters. Follow your maker's schedule. Daikin recommends cleaning the air filters every 2 weeks, with water or a vacuum cleaner.
• Service the unit. The National Environment Agency (NEA) suggests checking the filter once a month, servicing aircon units regularly and having them inspected annually.
• Do not overload sockets. EMA says overloading power points may lead to over-heating and start a fire, and warns against "piggy-backing" multiple plugs into one socket with double adaptors.

If you ever see aircon smoke, leave the room and call 995 rather than trying to clean or check the unit. Servicing costs depend on the job, so compare aircon servicing prices before you book.

When to stop and call a professional

Keep the aircon off and get help if:

• The burning smell persists or returns.
• You see smoke, scorch marks or melted plastic.
• The breaker trips again.
• The isolator or socket is hot.

For smoke or fire, leave and call 995. If the breaker trips again, leave it off and call a Licensed Electrician. For a fault inside the unit, compare aircon companies. If the aircon keeps cutting the power, read our guide to aircon tripping the power.

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