Every split system has a pair of mesh filters behind the front panel of the indoor unit. They catch dust, pet hair and lint before the air reaches the cooling coil. When they clog, less air gets through, the unit works harder for the same result and your power bill goes up. A blocked filter is also the most common cause of a unit that ices up or drips water inside.
How often to do it
Every two to four weeks while the unit is in daily use. More often if you have pets, live on a busy road or have had building work nearby. Many units show a filter light after a set number of hours. Treat that as a reminder, not a fault.
The ten minute job
- Turn the unit off at the remote and wait for the louvres to close.
- Lift the front panel from the sides until it clicks and stays open.
- Slide each mesh filter down and out. They unclip with a gentle tug.
- Vacuum the dust off, or rinse under a lukewarm tap from the clean side.
- Shake off the water and let them dry fully in the shade.
- Slide them back in, close the panel and turn the unit on.
Do not use hot water, detergent or a hair dryer. The mesh is thin plastic and it warps. Never run the unit with the filters out, even for an hour, because dust goes straight onto the coil where you cannot reach it.
Where your part stops
The filters are the only part of the system an owner should touch. Please leave the rest alone. That means:
- Do not unscrew the casing or spray cleaner into the coil or fan.
- Do not touch the copper pipes or the valves on the outdoor unit.
- Do not hose the indoor unit or poke anything up the drain.
There is mains power behind that casing, and the refrigerant circuit is under pressure. Working on it is licensed work for good reason. Spray-can coil cleaners are a common cause of the service calls we get, because the loosened muck slides down and blocks the drain.
When clean filters are not enough
If the filters are clean and the unit still smells musty, blows weakly or drips, the dirt is deeper in: on the coil and the fan barrel behind it. That needs a proper wash with a bag and a pump, which is what a service and clean is. For most homes that is once every year or two.
If yours is due, we service split systems around Reservoir from $169.