01 — Common problems
What can go wrong with your air conditioning.
What's usually behind each symptom and what you can check yourself while the technician is on the way. Without touching anything inside.
It could be dirty filters and coils, low refrigerant gas because of a small leak, or a unit that's now too small for the room.
In the meantime · Clean the indoor unit's filters if you know how; it's the first thing the technician will check.
It's almost always the condensate drain being blocked or not sloping enough. The water that should go outside comes back into the room.
In the meantime · Switch it off and put a cloth underneath until it's been looked at. That way you avoid stains on the wall.
Vibrations usually come from loose brackets or an outdoor unit that isn't sitting properly; whistling sometimes comes from a problem in the circuit.
In the meantime · Notice whether the noise comes from the indoor unit or the outdoor one.
A musty smell is usually dirt built up in the coil and the tray of the indoor unit. A deep clean sorts it out.
In the meantime · Air the room and avoid using it for long periods until it's been cleaned.
Modern units protect themselves and warn you with a code. Each brand has its own list, and the code gives a good idea of what the fault is.
In the meantime · Write down the code shown on the display or the remote control, plus the make and model of the unit.
You need to decide the type of unit, its output based on the room's size and orientation, and where the pipes and the drain will run.
In the meantime · Take photos of the room and of the outside wall where the unit could go.