Annual aircon service on the Sunshine Coast - what's actually on the checklist.

The 12-point service, in the order we do it

A service is not a vibes check. Either we measure something or we do not, and if we do not measure it we cannot tell you whether the system is in trouble. The order matters because the cleaning has to happen before the gauges go on - a fouled coil will throw your superheat and subcooling readings out by enough to make a healthy system look sick. So the sequence is: filters first, indoor coil, blower wheel, drain tray and line, then outside to the condenser coil and fan, then electrical, then gauges last. About 90 minutes per indoor head on a residential split, longer on ducted because of plenum access.

Indoor side - what we see most

The Sunshine Coast climate is brutal on indoor coils. We sit in the humid subtropical band, so an air conditioner here pulls four to six litres of condensate out of the air on a typical wet-season day. That moisture plus household dust feeds a slime layer on the evaporator coil that you cannot see from the room - you have to lift the front face, drop the drain pan, and shine a torch up between the fins. About one in three units we open up has visible biofilm by year two, and almost all of them have it by year four. A coil chemical clean (we use a non-acid foaming cleaner, foam-on, dwell, fresh-water rinse) restores airflow and brings cycle times back to where the manufacturer specced them.

While the front is off we pull the blower wheel and check for cake. A blower with caked fins is moving 20 to 40 percent less air than nameplate, which means the system runs longer and harder for the same room temperature. If the wheel is bad enough it comes off and gets a separate clean - about an extra 30 minutes but worth it on any unit older than three years.

Condensate - the wet-season call-out we prevent

We flush the condensate line with compressed air and a wet-vac at the outdoor end, and where the run is long (ceiling-cassette installs, some Buderim and Sippy Downs second-storey jobs) we add a measured dose of biocide tablet into the tray. A blocked drain is the number-one wet-season call-out - it backs up and drips out of the indoor head, sometimes onto a ceiling. Flushing the line during the service heads it off completely for the next 12 months.

Outdoor side - gauge readings on paper

The outdoor condenser gets a fresh-water rinse from inside-out through the coil, fan-blade balance check, and a torque-screwdriver pass on the terminal block (loose connections cause about half the no-cool calls on systems older than seven years - pure heat, no fault code, until something melts). Then the gauges go on. We log static pressure, running suction and discharge pressures, suction-line and liquid-line temperatures, calculate superheat and subcooling, and write them on the service sheet. Year-on-year drift in those numbers is the cleanest early warning of a slow leak or a tired compressor we have.

The coastal-salt rotation

Within roughly a kilometre of open surf, the fin material on a standard residential condenser starts losing surface area to chloride corrosion inside three to four years. The damage is cumulative and invisible from a distance - the fins look fine, but a wire-brush pass turns up powder. Once it is there it does not come back. So for jobs in Mooloolaba waterfront, Alex Headland, Maroochy Beach foreshore, Kings Beach, Coolum Beach, Marcoola, Sunshine Beach, Peregian and Noosa Heads, we run a half-year fresh-water rinse plus a polymer-based corrosion inhibitor on the coil. It is a 20-minute add-on at the May or November visit and it doubles realistic condenser life from around six years to twelve. If you are installing new in the salt zone, ask for a coastal-spec unit with a Blue Fin or epoxy-coated coil from the factory - Mitsubishi Electric's MSZ-AP series and Daikin's Cora coastal models are the two we fit most.

Reading the gauges - what slow leak looks like

On a healthy R32 split running in cooling at 28 degrees ambient and 22 degrees return, we expect suction pressure around 950 to 1050 kPa, discharge around 2700 to 3000 kPa, suction superheat of 5 to 10 degrees and subcooling of 8 to 12 degrees. The number that moves first when refrigerant is low is suction superheat - it climbs because the evaporator is starved, the last bit of liquid boils off too early in the coil, and the suction line warms up before the gas reaches the compressor. A superheat reading of 15 degrees on the same system is a slow-leak flag. We follow up with an electronic sniffer, brake-cleaner-and-bubble-soap pass on the flare joints, and if needed UV dye in the system for a two-week recheck. Topping up a system with an active leak is illegal under the ARCtick licensing rules - refrigerant gas is a scheduled greenhouse substance, and we are not allowed to vent it knowingly. So if there is a leak we find it and fix it, or we walk away.

What an honest service quote looks like

Single split, on-coast, annual: typically $160 to $220 including filter and coil clean, drain flush, electrical check and gauge readings on paper. Multi-head: $130 to $160 per indoor head when done on the same visit. Ducted: $280 to $380 because plenum access takes longer. Salt-zone six-month rotation: $130 add-on for the rinse and inhibitor. If we find a fault during the service - capacitor under voltage rating, contactor pitting, fan-bearing noise, suction superheat outside spec - we quote the repair separately and only proceed with your sign-off. A service should never become a surprise bill.

Book the next service

We service Maroochydore, Mooloolaba, Buderim, Caloundra, Kawana Waters, Sippy Downs, Nambour, Noosa, Coolum and the hinterland. ARCtick refrigerant handling licence AU-style number on every invoice, QBCC contractor licence visible on the quote, fully insured. Book online via the quote form or email quotes@sunshinecoastairconservice.com.au with your suburb and brand of unit and we will come back the same day with a window.

FAQs about annual aircon servicing on the Sunshine Coast

What is actually on the 12-point annual service checklist?

The full 12 points: indoor filter wash, evaporator coil chemical clean, blower-wheel inspection, condensate tray and drain flush, outdoor condenser coil rinse, fan-blade and bearing check, electrical-connection torque check, capacitor microfarad test, contactor inspection, refrigerant pressure reading high and low side, superheat and subcooling calculation, and a discharge-line temperature check at the compressor. We hand over the readings on a one-page printout so you can compare year-on-year.

Why do coastal Sunshine Coast homes get a 6-month rotation?

Inside about a kilometre of open ocean the salt-laden onshore breeze accelerates fin corrosion. Five-year-old condensers in standard residential trim can lose 30 to 40 percent of fin surface area, which kills heat-rejection efficiency. A six-monthly fresh-water rinse plus polymer inhibitor on the coil doubles realistic lifespan, so we book salt-zone jobs for May and November.

What does a refrigerant gauge reading tell you about a slow leak?

Suction superheat is the first number to move. On an R32 split specced for 5 to 10 degrees of superheat, a reading of 15 to 25 degrees is a strong slow-leak flag. We follow up with a sniffer test and UV dye rather than a top-up - under the Ozone Protection Act we are not permitted to knowingly recharge a system with an active leak.

When do you recommend a regas versus a repair-then-regas?

If charge is low and a thorough leak hunt finds nothing on a unit under eight years old with no prior gas history, an honest regas is reasonable - sometimes a flare joint weeps tiny amounts over years. If the sniffer locates a leak at a coil, valve or line, we repair first and recharge after. We never top up a known-leaking system; it is an ARCtick licence breach.