Preparing Your Air Conditioner for Australian Summer

Australian summers are relentless. When the mercury climbs past 40°C in many parts of the country, your air conditioner isn't just a luxury—it's essential for health and safety. The worst time to discover your AC has problems is during a heatwave when every technician in town is booked solid. This guide helps you prepare your air conditioner before summer hits, ensuring reliable cooling when you need it most.

The Pre-Summer Checklist

Complete these tasks in late winter or early spring—ideally September or October—while the weather is still mild and HVAC technicians have availability.

Step 1: Clean or Replace Air Filters

Filters that have been idle for months accumulate dust even when not in use. Dirty filters are the number one cause of reduced cooling performance and increased energy consumption.

• Remove all filters from your indoor unit(s)
• Vacuum off loose dust
• Wash with lukewarm water and mild detergent
• Allow to dry completely (2-3 hours minimum)
• Replace filters that are damaged, discoloured, or excessively worn

Step 2: Inspect and Clean the Outdoor Unit

Your outdoor condenser has been exposed to weather, leaves, debris, and potentially spider webs for months. It needs attention before working hard through summer.

Check for and address:

• Debris: Remove leaves, grass clippings, and any material blocking the unit
• Vegetation: Trim plants to maintain at least 50cm clearance on all sides
• Dirt on fins: Gently hose down the condenser fins (use low pressure, spray from inside out)
• Bent fins: Carefully straighten any bent fins with a fin comb if needed
• Level placement: Ensure the unit is still level on its mounting pad
• Unusual sounds or vibrations: Turn on briefly to check operation

Step 3: Check the Condensate Drain

Air conditioners remove moisture from the air, which drains away through a condensate line. A blocked drain can cause water leaks inside your home or trigger the unit to shut down.

• Locate your condensate drain (usually a small pipe exiting near the outdoor unit)
• Check that water flows freely when the AC runs in cooling mode
• Clear any visible blockages from the drain opening
• Pour a cup of white vinegar through the drain annually to prevent algae buildup

Step 4: Test Your System

Run a full operational test before you desperately need cooling:

1. Turn on the cooling function at a moderate setting (around 24°C)
2. Allow the system to run for 15-20 minutes
3. Verify cold air is coming from all vents (for ducted) or the indoor unit (for split)
4. Listen for unusual sounds—grinding, squealing, or rattling
5. Check for any water leaks from the indoor unit
6. Smell for any musty or burning odours
7. Confirm the remote control works and batteries are fresh

Professional Pre-Summer Service

While the above tasks are DIY-friendly, scheduling a professional service before summer provides additional peace of mind. A technician will:

• Check refrigerant levels (low refrigerant indicates a leak)
• Test all electrical connections and components
• Clean evaporator and condenser coils thoroughly
• Verify thermostat accuracy
• Measure airflow and system performance
• Identify potential issues before they become breakdowns

Book early—by November, HVAC technicians are often booked weeks in advance.

Optimising Settings for Summer

Once your system is ready, optimise your settings for efficient summer operation.

Temperature Settings

The ideal indoor temperature for comfort and efficiency is 24-26°C. Setting your AC to 18°C doesn't cool the room faster—it just makes the system run longer and costs more.

• Start at 24°C and adjust if needed
• Use the "auto" fan setting for most situations
• Consider raising the temperature 1-2 degrees when you're away
• Don't turn off completely during heatwaves—a hot house takes far more energy to re-cool

Using Timer and Schedule Functions

Modern air conditioners have sophisticated timer and scheduling features. Use them to:

• Pre-cool your home before you arrive (set to turn on 30 minutes before you get home)
• Avoid cooling an empty house during work hours
• Automatically raise temperature overnight when cooler outdoor air helps
• Wake up to a comfortable bedroom without running AC all night

Zone Control for Ducted Systems

If you have ducted air conditioning with zone control:

• Close zones for unused rooms during the day
• Focus cooling on occupied living areas
• Switch to bedroom zones in the evening
• Never close more than 70% of zones (restricts airflow and stresses the system)

Complementary Efficiency Measures

Your air conditioner will work more efficiently with help from passive cooling strategies:

Shade and Insulation

• Close blinds and curtains on sun-facing windows, especially north and west
• External shading (awnings, shutters) is more effective than internal blinds
• Roof and ceiling insulation dramatically reduces heat gain
• Draught-proofing prevents cool air escaping around doors and windows

Reduce Internal Heat

• Use exhaust fans when cooking
• Run dishwashers and dryers in the evening when it's cooler
• Switch to LED lighting (less heat output than older bulbs)
• Avoid using the oven during the hottest part of the day

Ventilate When Appropriate

On milder days or cooler evenings:

• Open windows for cross-ventilation instead of running AC
• Use ceiling fans to circulate air with AC set higher
• Flush out hot air in the evening before switching to AC overnight

Emergency Preparedness

Despite best preparation, breakdowns can happen. Be ready:

• Save the contact details of a reliable HVAC technician before you need one urgently
• Know where your AC isolator switch is located
• Have portable fans as backup for non-critical areas
• Know your nearest air-conditioned public spaces (libraries, shopping centres) for extreme heat emergency backup
• Keep hydrated—know the signs of heat stress

Summer Maintenance During the Season

Throughout summer, continue basic maintenance:

• Clean filters every 2-4 weeks during heavy use
• Check outdoor unit clearance periodically
• Listen for any changes in how your system sounds
• Monitor energy bills for unexpected increases (may indicate problems)
• Clear any water from drip trays if you notice buildup

A little preparation now ensures your air conditioner performs reliably through the long Australian summer. Don't wait until the first heatwave to discover an issue—complete your pre-summer checklist today and enjoy cool comfort when you need it most.

For detailed maintenance instructions, see our complete AC maintenance guide.