Hi all,

Been called to a airedale UCCU70SQ-2/1 on 407c which will not start. There isn't any active alarms. The indoor temperature is high enough to call for cooling but nothing. On startup the compressor contactor goes in and out right away then the unit does nothing. I've checked the alarm log and there is a historic trip diff pressure C1 and low differential pressure both from last month. I've checked the sensor pressures which read the same as my gauges. Any thoughts welcome