looking at an ice cream machine it had a new compressor fitted to it by another engineer but he never finished it. So i changed the drier, vacuumed and topped up with gas. The system was r12 but the new comp was r134a. I've used r409 gas.Now when ever its turned on there is no heat in the liquid line plus the discharge is'nt as warm as it should be, but the suction is freezing. It pulls the first few ice cream ok but is taking to long to prime after.Then when it is turned off the suction line loses it's freeze stright away then there is like a whistle sound like gas leaving the chamber. any thoughts??

ps mod's i put this in domestic by mistake sorry