1. After the Aircon is on for about 10mins, water start to leak out for the Aircon u it. 2. The Aircon has been serviced and chemical clean 3 months ago.
There are actually many reasons which cause your air-con to have water leaking problem. Since you had done a chemical wash last 3 months ago. There are some other areas which you can look into:
1. The gradient of the drainage pipe.
You can look at the trunking which is being installed on the wall. Check whether does it had a slight gradient.
2. Long drainage pipe.
The drainage pipe from the indoor fan coil unit to the toilet might be too long. Causing the drainage pipe to get clog easily.