Samsung VRF DVM Error code E-153

[Oketch]

I have an ac dvm system outdoor supply five indoors four are working well but is showing error code e153 have tried to replace float switch but sometimes it can work for a week then it’s bring again the error. What could be the problem with a system please help.

 

[App]

E153: Floating Switch detection of fan coil unit Drain Pump. Rise in drain board water level or faulty sensor due to malfunction of fan coil unit drain pump.