What should I check first when my split system blows warm air?
Start with the remote. Make sure the unit is set to cool, not heat, fan or dry. Auto mode can pick the wrong setting on a mild day. Set the temperature a few degrees below the room temperature and give it ten minutes. Check the remote batteries, and check the unit has power at the isolator and the switchboard.
Then look at the filters. Slide them out. If they are furry with dust, wash them in lukewarm water, dry them fully and refit them. Next, check the outdoor unit. Leaves, long grass, stored boxes or a fence set too close stop it getting rid of heat. Clear the area, turn the power off for a few minutes, then restart.
Why would a split system run but not cool?
If the basics are fine, the fault is usually inside the system. Low refrigerant is a common one. Refrigerant is not used up, so low gas means a leak. Signs include ice on the indoor coil or the outdoor pipes, a hissing sound, and long run times with weak cooling. Topping up without finding the leak only delays the problem. Handling refrigerant needs an ARC authorised technician, so this is not a DIY job.
Other causes include a failed capacitor or fan motor in the outdoor unit, a compressor fault, a dirty indoor coil, a faulty temperature sensor, or a reversing valve stuck in heating mode. Coastal conditions add to this. Humid air and dust clog coils faster, and salt air near the beach corrodes outdoor units over time.
Why is my ducted system cooling some rooms but not others?
Ducted systems add airflow problems. A dirty return filter, closed zones on the controller (such as an AirTouch 5), a crushed or disconnected flexible duct in the roof, or poor duct insulation can all leave rooms warm. Sunshine Coast roof spaces get very hot in summer, so a poorly insulated duct loses its cooling before the air reaches the room.
Return air matters too. Our rule of thumb is that a 10 to 14 kW ducted system takes a 900 x 500 return grille, and 16 kW and above takes a 900 x 550. A return that is too small starves the system of air. It then cools poorly, ices up or trips out. This is a common fault on systems that were not designed with enough return air.
When should I call a technician or think about replacing the system?
Switch the system off and call a technician if it still blows warm air after the checks above. Do the same if you see ice, water leaking inside, a tripping breaker, a burning smell or loud noises. Running a faulty system can turn a small repair into a compressor failure. An older system with repeated faults, or one that was never the right size for the space, may be better replaced than repaired.
Repair cost depends on the fault, the parts, the access and the brand. Delta Temp is based in Baringa and services the Sunshine Coast from Caboolture to Noosa, but not Gympie. We are QBCC licensed, ARC authorised and insured. For a ducted replacement we do a free site inspection first, and the quote is fixed after that. Installations carry a 10 year workmanship warranty, and manufacturer warranties are 5 years for Fujitsu and 7 years for Hisense, parts and labour. Finance is available through humm for approved applicants. Regular servicing, including through our Comfort Club plan, helps catch dirty coils and slow leaks early. Call 1800 335 828.
