4: Freon leaks
If somewhere of gas pipe break, freon / gas might leaks. It could cause bad smell. You can find the oil mark around joint area.
5: Animal - birds / rat poop
If the outdoor unit install some where near the tree or behind restaurant. Bird poop might stay around the outdoor unit.
6: Connect to dirty water pipe
Sometime dirty water smell might flow back to the air con if technician did not connect it in the right way.
If you have question about your air con, please feel free to contact us : hkaircon.repair@gmail.com
our service area: pokfulam air con repair, sia kung ac serve, yuen long air con cleaning, tuen mun air con service, gold coast tuen mun, Tsing Yi air con cleaning, Tsuen Wan, TST air con service