Before calling for service, check the following: the unit is plugged in and the socket is working; the thermostat is set correctly; the condenser is free of dust; there is enough ventilation space around the unit; the door is closing and sealing properly; the unit is not overloaded or blocking internal air vents; and the unit is away from direct sunlight or heat sources. If none of these resolves it, contact your point of purchase or local distributor.