Annual servicing for homes, six-monthly for commercial. Here's what that actually buys you, and what a real service includes.
The short answer
Residential split and ducted systems should be professionally serviced once a year, ideally in spring. Commercial equipment and any system running long hours should be serviced every six months. Evaporative coolers need an annual pre-summer service and a pad replacement every three to five years.
What you should do yourself
Filter cleaning is the one job worth doing between services. Wash indoor filters every four to six weeks in heavy use — a clogged filter reduces airflow, drops capacity and can freeze the indoor coil.
What a professional service includes
A genuine service measures performance rather than just looking at the unit.
- Refrigerant pressures, superheat and subcooling measured and compared to spec
- Electrical testing: compressor and fan amp draw, capacitor capacitance, contactor condition
- Indoor and outdoor coil condition and cleaning
- Condensate drain flush and drain tray sanitising
- Supply air temperature split measured at the outlets
Why it pays for itself
A system with dirty coils and a slightly low charge can use noticeably more power for less cooling. Servicing restores capacity, extends compressor life and catches small electrical faults before they cause a mid-January failure — when demand for technicians is at its peak.