Thanks, that issue is already sorted as I got a new aftermarket condenser in.. all in all I paid £320 but now I am getting this hissing noise from aircon (video above).. trying to find a solution for it as it is so annoying!
Check the pressures (low and high side). I'm not sure about the W204 but on many MB's since the W210, you can read it right off the climate control panel when in diagnostic mode. I suspect that you're a little low.