Hi guys
I have been to a system this week which was not running. I started up and system seemed to run fine but have attended next morning to find L8 fault which I understand to be a compressor issue. I reset again and same result following morning, L8 fault present. when now reset slave condensor runs but nothing on master, compressor starts but then stops.
ran a test mode and got UF??

system is as follows
REYQ14M8W1B MASTER
REYQ16M8W1B SLAVE

APPROX 9 INDOOR UNITS

cant phone technical from site of condensers, is it just a faulty main/inverter compressor??
any tips appreciated, thanks.