Category: Air Conditioning

Air conditioners rely on a steady and safe electrical supply to work properly. When something goes wrong electrically, the system may stop working, trip the power, shut down without warning, or give off warning signs like burning smells or error codes.

In Perth homes, many aircon faults are electrical rather than mechanical, and they often come from power supply issues, ageing components, or installation problems. Knowing the common electrical problems and what they mean helps you act early, avoid safety risks, and get the right professional help before damage gets worse.

Below, we break down the most common electrical air conditioning problems, explain why they happen, and outline what to do when they occur.

WA safety note: In Western Australia, DIY electrical work is dangerous and should not be done. By law, electrical work on your home must be carried out by a licensed electrician (or appropriately licensed technician).

Key Summary: Common Electrical Problems in Aircons

1. Air conditioner will not turn on
2. Circuit breaker or safety switch keeps tripping
3. Outdoor unit not running
4. Contactor failure
5. Capacitor failure
6. Air conditioner turns off by itself
7. Thermostat or thermostat wiring fault
8. Control board failure
9. Communication faults between indoor and outdoor units
10. Burning smell from the air conditioner
11. Air conditioner trips power on startup
12. Undervoltage or poor power quality
13. Incorrectly sized electrical circuit
14. Loose or degraded wiring and terminals
15. Moisture-related electrical faults
16. Age-related electrical degradation
17. Error codes and warning lights

1. Air conditioner will not turn on

This fault occurs when electrical power is interrupted before it reaches the system, which completely prevents the air conditioner from operating even if the unit itself is not mechanically faulty.

This is one of the most common electrical aircon problems and usually points to a loss of power somewhere between the switchboard and the unit.

Typical causes:

• Tripped circuit breaker or blown fuse
• Faulty isolator switch
• No power supply to the unit
• Failed control board
• Loose or damaged wiring

What to do:

1. Check the breaker and isolator are ON (no opening anything).
2. If it still won’t start, leave it off and book a licensed electrician/tech.

2. Circuit breaker or safety switch keeps tripping

This happens when the air conditioner draws unsafe current or electricity leaks to earth, causing the protection device to cut power to prevent overheating, damage, or fire.

Frequent tripping is a warning sign that should never be ignored or repeatedly reset.

Common electrical reasons:

• Short circuit inside the unit
• Overloaded circuit
• Faulty compressor drawing excess current
• Moisture inside electrical components
• Undersized wiring or breaker

What to do:

1. Stop resetting it repeatedly.
2. Switch the system off at isolator.
3. Leave the breaker OFF and call a licensed electrician.

3. Outdoor unit not running

This fault means electrical power is not being correctly delivered to the outdoor components, stopping the compressor from operating and preventing heating or cooling.

The indoor unit may still run and blow air, but without the outdoor unit there is no temperature control.

Electrical causes include:

• Failed contactor
• Faulty capacitor
• No power to the outdoor unit
• Safety cut-out activated
• Loose terminals or burnt connections

What to do:

1. Turn system off.
2. Check isolator is ON and note any error code.
3. Book a licensed electrician/tech to test supply and controls.

4. Contactor failure

A contactor failure prevents electrical power from being switched through to the compressor, leaving the system powered but unable to start under load.

This fault often goes unnoticed until electrical testing is carried out.

What happens:

• Power is present but not passed through
• Outdoor unit remains completely inactive

What to do:

1. Turn unit off and don’t keep trying to start it.
2. Book a licensed tech to test and replace parts.

5. Capacitor failure

When a capacitor fails, motors cannot receive the electrical boost needed to start, which causes hard starts, tripping, or complete failure to run.

This is one of the most common electrical faults in residential air conditioners.

Symptoms include:

• Unit hums but does not start
• Compressor or fan struggles to engage
• Circuit trips during startup

What to do:

1. If it hums or struggles, turn it off.
2. Do not restart repeatedly.
3. Book a licensed tech.

6. Air conditioner turns off by itself

This occurs when electrical protection systems detect unsafe conditions and shut the unit down to prevent component damage.

The shutdown may appear random but is usually triggered by a measurable electrical issue.

Possible reasons:

• Overheating electrical components
• Loose wiring
• Faulty sensors
• Control board errors
• Voltage supply problems

What to do:

1. Note when it happens and any error code.
2. If it repeats, stop using it and book a licensed tech.

7. Thermostat or thermostat wiring fault

Faulty thermostat wiring sends incorrect electrical signals, causing the air conditioner to make the wrong decisions about when to start, stop, or cycle.

This issue can easily be mistaken for a performance or temperature problem.

Electrical signs include:

• Ignoring temperature settings
• Short cycling
• No response to control changes

What to do:

1. Replace remote batteries if applicable.
2. Note symptoms and error codes.
3. Book a licensed tech to test controls and wiring.

8. Control board failure

A failed control board disrupts the electrical commands that manage every function of the air conditioner, leading to unpredictable behaviour or total shutdown.

Modern systems rely heavily on electronics, making this fault increasingly common.

Causes include:

• Power surges
• Moisture damage
• Age-related component failure

This can affect:

• Starting and stopping
• Temperature regulation
• Communication between units

What to do:

1. Turn it off if behaviour is erratic.
2. Note error codes/lights.
3. Book a licensed tech.

9. Communication faults between indoor and outdoor units

This fault occurs when electrical communication signals between the indoor and outdoor units are interrupted, preventing them from operating in sync.

It is particularly common in inverter and newer split systems.

Electrical causes:

• Broken communication wiring
• Incorrect voltage supply
• Failed control boards

Often shown as error codes or flashing lights.

What to do:

1. Record the exact error code.
2. Power the system off and leave it off if it repeats.
3. Book a licensed tech.

10. Burning smell from the air conditioner

A burning smell indicates overheating or electrical arcing, which can quickly lead to serious equipment damage or fire risk.

This should always be treated as urgent.

Electrical causes:

• Overheating wiring
• Burnt terminals
• Failing motors
• Melted insulation

What to do:

1. Turn it off immediately.
2. Switch off at isolator or breaker.
3. Do not use again until inspected by a licensed electrician.

11. Air conditioner trips power on startup

Startup draws the highest electrical load, and if components cannot handle it the safety system cuts power immediately.

This issue often appears suddenly, even if the unit worked previously.

Common reasons:

• Weak or failed capacitor
• Ageing compressor
• Undersized electrical circuit
• Poor supply voltage

What to do:

1. Stop attempting restarts.
2. Leave breaker off if it trips again.
3. Book a licensed electrician to test the circuit and unit.

12. Undervoltage or poor power quality

Low voltage forces the air conditioner to draw higher current to compensate, which increases heat, stress, and failure rates.

This problem often originates from the home’s electrical system rather than the air conditioner itself.

Causes include:

• Long cable runs
• Older switchboards
• Shared circuits
• Utility voltage drops

What to do:

1. Note timing (hot afternoons, peak load).
2. Stop using the unit if faults repeat.
3. Book a licensed electrician to test supply and circuit.

13. Incorrectly sized electrical circuit

An undersized circuit cannot safely supply the current the air conditioner needs, leading to ongoing electrical stress and repeated faults.

This is usually an installation issue that only becomes obvious over time.

Results include:

• Frequent tripping under load
• Overheating cables
• Shortened component life

What to do:

1. Do not change breakers or “upgrade” anything yourself.
2. Stop using it if tripping continues.
3. Book a licensed electrician to assess the circuit.

14. Loose or degraded wiring and terminals

Loose or damaged wiring increases electrical resistance, creating heat build-up that leads to intermittent faults or safety risks.

This is especially common in older systems and installations.

Includes:

• Brittle insulation
• Corroded terminals
• Burnt connections
• Poor original workmanship

What to do:

1. If you notice burning smell, buzzing, or repeated trips, switch off.
2. Book a licensed electrician to inspect.

15. Moisture-related electrical faults

Moisture creates unintended electrical paths that trigger safety devices and cause corrosion-related failures.

Outdoor units are particularly vulnerable to this type of fault.

Moisture can cause:

• Short circuits
• Earth leakage trips
• Corrosion on boards and terminals

What to do:

1. If it started after heavy rain or washing down, switch off.
2. Do not try to dry/open the unit.
3. Book a licensed tech to inspect.

16. Age-related electrical degradation

Over time, electrical components lose efficiency and reliability, even when the air conditioner still appears to function normally.

Electrical wear often occurs long before mechanical failure.

This includes:

• Capacitors weakening
• Contactors pitting
• Control boards failing
• Wiring insulation breaking down

What to do:

1. If the system is older and faults are increasing, book a preventative inspection.
2. Discuss repair vs replacement with a licensed pro.

17. Error codes and warning lights

These appear when electrical readings fall outside safe operating ranges, signalling faults before major damage occurs.

They are indicators, not fixes, and still require proper diagnosis.

These usually indicate:

• Power supply issues
• Sensor faults
• Communication errors
• Control board problems

What to do:

1. Write down the code.
2. Turn the unit off if the fault repeats.
3. Book a licensed tech and give them the code.

Have a problem that needs fixing? Contact an electrician for a consultation and assessment

Electrical problems in air conditioners should never be ignored. Issues like repeated tripping, burning smells, units cutting out, or outdoor systems not running can point to unsafe electrical conditions that only get worse over time.

While homeowners can safely turn systems off and note what is happening, electrical testing and repairs must always be carried out by a licensed electrician or authorised air conditioning technician in WA. Attempting DIY electrical work is unsafe and illegal.

If your air conditioner is showing any of the issues covered above, we recommend having it checked early to prevent breakdowns, fire risk, or costly damage.

Need help with an aircon servicing and repairs in Perth?

Contact Limelight Electrix today. We provide clear advice, upfront pricing, and a free electrical safety check with every service, so you can get your home back to safe and reliable cooling with confidence.

Keeping your air conditioning system in top condition is essential for staying comfortable during Perth’s hot summers and maintaining a healthy indoor environment. But how often should you service your aircon? Let’s break it down to help you keep your system running efficiently year-round.

Recommended Servicing Frequency

Most aircon experts, including our team at Limelight Electrix, recommend an annual service for your air conditioner. Regular maintenance identifies potential issues before they escalate, keeps the system efficient, and ensures it operates smoothly when you need it most. This proactive approach helps avoid costly repairs and maximises the lifespan of your unit.

Recommended Frequency by Aircon Type

• Split Systems: These require servicing at least once a year.
• Ducted Systems: Due to their complexity, ducted systems also benefit from annual checks to inspect ducts and connections.
• Evaporative Coolers: These need more frequent attention—ideally twice a year—to maintain optimal performance.

Best Time to Service Your Aircon in Perth

The ideal time for servicing your home air conditioner in Perth is during spring, typically in October or November. Here’s why:

• Preparation for Summer: Get your aircon ready before the scorching summer heat kicks in. A spring service prevents unexpected breakdowns during peak demand.
• Avoiding the Rush: HVAC professionals are often booked out closer to summer. Servicing in spring gives you quicker access and more flexible scheduling.
• Improved Efficiency: Regular maintenance enhances efficiency, saving you energy costs when temperatures soar.
• Better Air Quality: Cleaning or replacing air filters during servicing reduces allergens, dust, and mould, promoting healthier indoor air quality.

Seasonal Timing Tips for Aircon Servicing

While an annual service is the general recommendation, a more tailored seasonal approach can help optimise your air conditioner’s performance throughout the year. Here’s a closer look at why spring and autumn are ideal times for servicing.

Spring Servicing

Scheduling aircon maintenance in spring—before summer’s heat sets in—ensures that your unit is ready to perform at peak efficiency. This proactive approach helps prevent surprise breakdowns during the hottest months and maximises cooling performance for the upcoming season. With HVAC demand lower in spring, you’ll also benefit from faster booking times and often more flexible scheduling.

Autumn Servicing

As summer winds down, your air conditioner can benefit from a thorough clean-up after months of heavy use. Autumn is the ideal time to clear out accumulated dust and debris, which keeps internal components in good shape and maintains the air quality in your home. A post-summer service also helps your system recover from the strain of constant use, preparing it for longevity through the cooler months and into the next summer.

Adapting your servicing routine to these seasonal timings keeps your air conditioner efficient, reduces energy costs, and helps prevent wear and tear from building up over time.

Signs Your Aircon Needs Servicing

If you’re unsure whether it’s time for a service, watch out for these signs:

• Insufficient Cooling: Struggling to maintain the desired temperature? It could indicate refrigerant issues or clogged ducts.
• Increased Energy Bills: A sudden spike may signal that your system is working harder than it should.
• Unusual Noises: Buzzing, rattling, or grinding sounds suggest internal problems.
• Strange Odours: Musty or burning smells may indicate mould or electrical issues.
• Poor Airflow: Weak airflow can result from blocked filters or duct obstructions.
• Water Leaks: Pooling water around the unit is a sign of a blocked drain or frozen coils.
• Frequent Cycling: If your aircon keeps turning on and off, it might be struggling with temperature regulation.
• Age of the Unit: Older units (10+ years) often need more frequent servicing.

Why Regular Aircon Servicing Matters

Regular maintenance isn’t just about avoiding breakdowns—it offers multiple benefits:

• Energy Efficiency: A well-maintained system uses less energy, saving you money on power bills.
• Extended Lifespan: Routine servicing prevents small issues from turning into costly repairs, prolonging your unit’s life.
• Improved Air Quality: Clean filters and components reduce allergens and keep your indoor air fresh.
• Reliable Performance: Stay cool when it matters most with consistent performance.
• Health Benefits: Cleaner air means fewer allergens and respiratory irritants in your home.

What’s Included in a Limelight Electrix Aircon Service

At Limelight Electrix, we offer a comprehensive aircon service to ensure your system performs at its best:

• Preventative Maintenance: Regular servicing to enhance system longevity and efficiency.
• Comprehensive System Check: Thorough inspection of all components to ensure optimal performance.
• Cleaning and Filter Replacement: Removal of dust and contaminants to maintain air quality and system efficiency.
• Refrigerant Level Assessment: Checking and adjusting refrigerant levels as needed for effective cooling.
• Electrical Connection Inspection: Ensuring all electrical components are secure and functioning correctly.
• Operational Testing: Running the system to verify proper operation and identify any issues.
• Manufacturer-Specified Procedures: Adhering to the maintenance guidelines set by the air conditioning unit’s manufacturer.
• Free Safety Inspection: Conducting a complimentary safety check of your home’s electrical systems with every service.

Frequently Asked Questions

How do I know if my air conditioner needs servicing?

Watch for signs like reduced cooling, unusual noises, or increased energy bills.

Is it worth it to service your air conditioner?

Yes! Regular servicing ensures efficiency, lowers energy costs, and prolongs your system’s life.

What happens if an air conditioner isn’t serviced?

Without maintenance, your system can lose efficiency, develop costly faults, and circulate unhealthy air.

Regular aircon servicing is essential for efficient performance, lower energy costs, and a comfortable home environment. By keeping your unit in top shape, you’ll avoid costly repairs and enjoy reliable cooling when it matters most. Ready to book your service? Book an Air Con Servicing & Repairs quote with Limelight Electrix or call our experts to discuss your needs and ensure your aircon is summer-ready!