Same problem with me - beeping sound randomly but especially when water heater switch is on. At first thought wiring problem, but if really fan problem then it's less headache ... phew ...

I'm still waiting for my friend to come and check the wiring but can't wait forever. The fan is in my bedroom, it's start randomly beeping in the middle of the night and wakes up my baby ... my wife is getting very impatient and bugging me to get the solution ....

If can't wait then I'll just replace the fan much faster ... haha

Hmm just read a few feedbacks and comments from other threads and Lazada - it seems possibly could be motherboard, remote sensor or motor problem. But all of them recommends if still under warranty, call Deka customer service and ask them to go and have a look, you could get free part replacement.

I'm going to give them a call and just ask them to have a look, since they are the experts in their own stuff after all