What's wrong with air conditioner f4?

What's wrong with air conditioner f4? F4 indicates that the indoor pipeline temperature sensor is faulty.

1. The induction cable is broken. It may be worn off or bitten by a mouse, especially the air conditioner in the hotel.

2. The filter screen is blocked by dust because it is not cleaned for a long time, which leads to the cold air of air conditioning refrigeration can not be blown out in time, resulting in low temperature in the machine and poor protection.

3. The capacity of the internal fan is reduced, which leads to the low rotation speed of the internal fan and the cold air cannot be blown out in time.

4. The top of the internal evaporator is too dirty, which leads to the lack of ventilation of the evaporator.

The answer is applicable to Midea KFR-26GW/N8mJA3 &; & Gree KFR-35GW/NhAa 1BAj and other brands.