Is your air conditioner running but not cooling? You’re not alone. This is one of the most common questions homeowners ask online, especially during Melbourne’s unpredictable summers.
In this guide, we break down the most likely reasons your split system or ducted AC is blowing warm air, and what to do about it.
The Thermostat Is Set Incorrectly?
It sounds simple, but we’ve seen it time and time again. Your AC might be on, but the thermostat could be set to fan-only mode or a higher-than-needed temperature.
Check:
- Mode is set to “Cool”
- Temperature is lower than room temp
- Fan is on Auto, not On
Clogged Air Filter?
In dusty Melbourne suburbs (especially near construction zones), your air filter can clog quickly. A dirty filter restricts airflow and can cause the system to blow warm or no air at all.
Solution:
Clean or replace your AC filter every 3 months, or monthly during peak use.
Low Refrigerant (Gas)?
Your system might be low on refrigerant, especially if it’s an older unit or hasn’t been serviced in years. Without enough gas, your AC can’t cool effectively and it might freeze over.
Call a licensed technician.
Refrigerant must be topped up by a licensed HVAC pro, and we can check for leaks while we’re there.
Dirty Outdoor Unit?
Your outdoor condenser (the box outside your home) needs to breathe. If it’s clogged with leaves, dust, or cobwebs, it can’t release heat properly which means your indoor unit won’t cool down the room.
Check:
- Nothing is blocking airflow around the outdoor unit
- Fins are clean and undamaged
- You haven’t accidentally enclosed the unit behind a fence or shed
Electrical or Capacitor Issue?
Sometimes, the indoor unit works fine, but the outdoor unit doesn’t kick in. This often points to a faulty capacitor or electrical issue that needs diagnosis.
Book a repair tech if:
- The outdoor fan isn’t spinning
- You hear a buzzing or humming sound
- There’s no cool air even though the indoor unit is working
Aged or Failing System?
If your unit is 10 years old or more, it might simply be on its last legs. Newer systems are far more energy-efficient, quieter, and better suited to Melbourne’s modern insulation standards.
We recommend:
An inspection to determine if repair or replacement makes more financial sense. We’ll give you honest advice, not a hard sell.
It Just Needs a Service?
Sometimes, the fix is simple. Your system just needs a professional tune-up. A seasonal service can:
- Clear out debris
- Detect early signs of failure
- Top up refrigerant
- Restore cooling efficiency
Quick Checklist Before You Call:
- Thermostat settings
- Clean filter
- Clear outdoor unit
- Still not cooling? Time to call a pro
Need Help Fast? We’re Melbourne’s Trusted Air Conditioning Repair Experts.
At Melbourne Gas & Air, we’ve serviced hundreds of split systems and ducted units across the city. Whether it’s a quick fix or a full system replacement, we’ll get your home cool again fast.
Book your service online or call us for a quote.
We offer same-day callouts across Melbourne metro and surrounding suburbs.