Tried searching but does anyone know a good refrigeration mechanic in Chiang Mai? Preferably a good guy with his own workshop,  not just the big electrical service centre like amorn etc. 

Not 100% on this as it was a while ago, but you might like to try out this place: Dragon Air (053 854 878) on the 1001, just up from Thepahya Hospital. This is the route that heads out to Mae Jo from the Superhighway (west of CentralFestival). Used them for cleaning a few times, did a good job. Quite a small outfit.

Thanks,  I'll give them a call. 

They only do air-conditioning.