1. Dirty or Blocked Filter
Your system pulls warm air through a filter, cools it and pushes it back into the room. When that filter is clogged — and in a Gold Coast home it happens faster than you’d think, especially if you have fur babies who like to nap in front of the warm air the outdoor unit pushes out — the system can’t pull enough air to do its job. It runs, it tries, it just can’t keep up.
Do this right now: Turn the system off for 30 minutes. Pull the filter from behind the indoor unit front panel. If it’s grey and clogged, rinse it under cool water, let it dry completely, reinstall and try again. If that’s not the problem — keep reading.
2. Refrigerant Leak
Very common — and the most misunderstood.
Refrigerant doesn’t get used up. It runs in a sealed loop. If your system is low on refrigerant, there is a leak somewhere. Full stop.
A regas without finding and fixing the leak is not just a temporary fix — it’s also illegal. Knowingly releasing refrigerant into the atmosphere is a breach of Australian refrigerant handling regulations. A licensed technician is required to locate the leak, repair it and only then recharge the system correctly.
Think of it like a bucket with a hole in it. Refilling the bucket doesn’t fix the hole. You fill it, it empties again, and you’re back where you started — except now you’ve paid for refrigerant that leaked straight out.
Here’s something most people don’t know — and most operators won’t tell you.
Every system leaves the factory with a precise refrigerant charge. That amount is specified for that exact system. If someone offers to ‘top it up,’ ask them this: how do they know how much is left? To know that, they’d need to recover the remaining refrigerant, weigh it, and calculate the shortfall. If they’re not doing that — they don’t actually know how much they’re putting in.
Pro tip: Take a look at your outdoor unit right now. There is a badge or data plate on the side of it. It tells you exactly which refrigerant type your system uses and precisely how much should be in it at all times. You can see for yourself — so can any technician who cares enough to look before they touch anything.
And here’s the part that really matters: the refrigerant still in your system after a leak has been contaminated by moisture and air that entered through the leak point. That gas cannot simply be reused. It needs to be recovered, disposed of correctly, and the system recharged from scratch with clean refrigerant to the manufacturer’s specified weight.
‘She’ll be right — just top it up and get it running’ is not a repair. It’s a gamble. And when the compressor fails six months later because it was running on the wrong refrigerant charge — that repair bill is yours, not theirs.
Cost done properly: Leak location, repair, refrigerant recovery and correct recharge — $800 to $2,500+ depending on the fault, refrigerant type and system size. It costs more than a quick top-up. It also actually fixes the problem.
3. Dirty Outdoor Condenser Coil
Particularly common in coastal areas — and Gold Coast’s salt air makes it worse.
The outdoor unit releases the heat your system pulled from your home. When its coils are covered in dust, salt deposits, grass clippings, seed pods, lint from nearby laundry vents and pet hair — the system can’t release heat efficiently. It works harder, overheats and can’t keep up with the cooling load.
This is one of the strongest arguments for annual servicing. A clean in April costs far less than a breakdown call in January.
4. Compressor Fault
Less common — but the big one when it happens.
The compressor drives the refrigerant around the loop. When it fails, the system runs but produces little or no cold air. A blown capacitor (relatively straightforward) and full compressor failure (significant) are both compressor faults — the diagnosis tells you which.
Age matters here. A compressor replacement on a 4-year-old premium system is worth doing. On a 14-year-old neglected system — probably not. We’ll always give you the honest assessment.
Cost: Capacitor replacement — $300 to $700. Full compressor replacement including new refrigerant — $1,100 to $3,500+ depending on system size and brand.
5. Thermostat or Sensor Fault
Confusing — because everything appears to be working normally.
Temperature sensors tell the system when the room has reached the set temperature. If they’re faulty, the system thinks the room is already cool and reduces output — or operates erratically and can’t hold temperature at all.
Cost: Sensor replacement — $400 to $1,200+. Control board replacement — $500 to $3,500+ depending on the brand and availability of parts.
Repair or Replace?
We get asked this on almost every call. Here’s our honest framework:
Repair makes sense when: the system is under 7 years old, has been regularly maintained and is in good overall condition. A well-looked-after system is worth investing in.
Replacement makes more sense when: the system is over 8 years old and hasn’t been regularly serviced or maintained. Also when the brand is a lesser-known one that may no longer exist — because if the brand is gone, so are the parts. Waiting on a backordered part for a discontinued system is not a situation you want to be in mid-summer.
The age alone doesn’t tell the whole story — a well-maintained 9-year-old Daikin is a very different conversation to a neglected 6-year-old no-name unit. We look at the full picture and give you our honest assessment every time.
Frequently Asked Questions
Why is my air conditioner running but not cooling?
Most likely a dirty filter, refrigerant leak, dirty outdoor coil, compressor fault or sensor issue. Most are fixable on the first visit with the right diagnosis.
Can I fix it myself?
You can clean the filter — and you should. Everything else needs a licensed technician. Refrigerant work is legally required to be performed by an ARCtick licensed professional in Australia.
How quickly can you attend on the Gold Coast?
If we installed your system or have previously carried out a repair on it — we attend within 48 business hours across the Gold Coast and South Brisbane. That’s our commitment to our own customers.
System Not Cooling? Let's Fix It.
Don’t leave it running under load. The longer a fault goes untreated, the more strain it puts on other components — and the more expensive the eventual repair can become.
If we installed your system or have previously worked on it, we attend within 48 business hours. We diagnose accurately, explain what we find in plain language, and back every repair with our lifetime workmanship warranty.
- Call (07) 5500 2826
- Text 0482 083 904
- info@tempercool.com.au
Or fill in our quick form here.
