Most air conditioners cause moist air to condensate, which is then caught and channeled away via drains.
Due to the increased number of Melbourne plumbers now installing these units with minimal experience, many drains are being incorrectly installed.
On more than one occasion Plumbfast has attended a commercial plumbing request and found the condensate drain sealed to a downpipe or drain without an air gap. The downpipe becomes blocked and the water from the unit then fills back up into the catchment tray and spills over customers and the wall.
On roof tops it is also common to see drains terminating onto metal roofing. This causes rapid corrosion and often ends in expensive roof repairs.
Ensure you employ a reputable commercial plumber when installing these units and avoid any unforeseen roof repairs.