Backtray choke

Over time, there will be forming in this part of the aircon. This will not be cleared with normal aircon servicing or chemical wash. However, during chemical overhaul, the coil will be fully dismantled, hence if water leaking is due to this issue, overhaul can solve the problem

Thorough cleaning

Most of the time normal aircon servicing can do the job in maintaining the aircon clean. However, over years of usage you may realised that there are certain parts of the aircon that will not be clean by normal cleaning, such as the back part of the evaporator coil, only chemical overhaul will be able to cover those areas.

Chemical residue

During normal chemical wash, no one can turn on the jet at full power, hence there will be some form of residue left on the evaporator coil. Overtime, this will corrode the coil, leading to you changing the fancoil unit. However, chemical overhaul will ensure maximum pressure, which will leave no residue on the coil. It will be rinsed many times throughout the process too.