Quick answer
If the airflow is weak, start with filters, blower, and fan coil cleanliness. If airflow is normal but air is warm, ask the technician to check refrigerant pressure, outdoor unit operation, capacitor, fan motor, and error codes before quoting major work.
Most likely causes
- Dirty filter, blower wheel, or evaporator coil restricting airflow.
- Outdoor condenser unable to reject heat properly.
- Low refrigerant caused by a leak, loose joint, or previous poor repair.
- Faulty capacitor, fan motor, PCB, sensor, or compressor.
- Unit too small for the room load or heavy afternoon sun exposure.
Safe checks before calling
- Check mode is set to Cool, not Fan or Dry.
- Clean filters and dry them fully before reinstalling.
- Set fan speed to high and check if airflow changes.
- Observe whether the outdoor unit is running.
- Check whether one room or the whole system is affected.
What to ask the technician
- What is the refrigerant pressure reading?
- If gas is low, where did the gas go?
- Did you check for a leak before topping up?
- Is the outdoor fan running and is the capacitor tested?
- Can you show why chemical wash or overhaul is needed?
Fair price range
General servicing is usually around S$25-S$80 per indoor unit. Chemical wash is roughly S$80-S$180 per unit. Gas top-up is often around S$80-S$250 depending on refrigerant and scope.