Troubleshooting
The air conditioner does not cool or heat: 8 causes to check before calling service
Five minutes of checks solve about half of the calls we get. Causes are ordered from the most common and easiest to the ones that need service.
4 min readUpdated
1. Wrong mode or setting
Fan or Dry instead of Cool, or a set temperature above the room. Set Cool and 24°C, fan Auto; for heating, Heat and 22°C.
2. Dirty filters
Weak airflow almost always means clogged filters. Wash them and give the unit 30 minutes; if the coil froze, switch off for an hour first.
3. Winter defrost
In heating mode the outdoor unit stops for 3–10 minutes and steams: normal. Thick ice that never melts means a blocked drain or low refrigerant.
4. The outdoor unit is not running
Indoor blows room air: check the outdoor fan. Overload protection, a tripped breaker or a failed capacitor. Power off for 5 minutes and retry; if it repeats, service.
5. Ice on the thin pipe in summer
A classic sign of low refrigerant, i.e. a leak. Do not top up blindly: the leak must be found and the system vacuumed and charged by weight.
6. An error code
Note the code (E1, F0, P4, U4…) and give it when you call so the technician brings the right part.
7. The unit is too small
Running flat out and the room stays above 27°C: not a fault, undersized. Check the capacity against area and exposure.
8. Water dripping indoors
A blocked or unsloped drain. Switch off and call; prolonged dripping damages the wall and the electronics.
Frequently asked questions
Why does it blow warm air in cooling mode?
Most often a wrong mode, a high set temperature, a stopped outdoor unit or low refrigerant.
Why does it stop by itself in winter?
Defrost cycles, normal below zero, lasting 3–10 minutes. If it stops for long and does not heat, check for ice on the outdoor unit and call us.
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