Thanks for the quick response, Jason.
Yes, the other 3 fancoil units are working fine. In fact, it is working last month, when the haze is the most serious, and then out of the blue, when we try to use it last week, it went on strike.
Just wondering, why it is possible that the wire will become faulty? broken?
As for the wiring, it should be exposed in the trunking. Have not opened the trunking to view what is inside.
Yes, my unit is old already, that's why my family is thinking of replacing the whole fancoil unit with a newer model, not sure if it is possible or not.
May I know how much do you charge for the investigation, and if we wish to do chemical servicing, how much will it be for all the 4 units?