What you'll notice
A sour or damp smell from the indoor unit, strongest in the first minutes after switching on, sometimes with visible dark growth on the coil fins.
Why it happens
Mould and bacterial biofilm on the permanently damp evaporator coil, in the blower wheel and in the drip tray. Coastal humidity makes this considerably faster to develop.
How we fix it
A chemical coil clean and rinse rather than a wipe, blower wheel cleaning, filter wash and a drain flush. The biofilm has to be physically removed; deodorising sprays mask it for days at most.
Still not working?
If the checks above haven't restored your evaporator coil & filters, this usually needs a technician. Our Aircon Cleaning & Sanitising service covers exactly this fault — from R700, quoted upfront.