Case Type: VRF Systems

Diagnostic troubleshooting of a 12-ton LG Multi V 5 heat recovery VRF system after two unsuccessful repair attempts. Communication was restored to all 9 indoor units and 3 heat recovery boxes, while testing identified a grounded compressor and additional conditions requiring evaluation before mechanical repair.

Mitsubishi City Multi heat recovery VRF diagnostics in Santa Monica after supply-air temperatures dropped to approximately 28°F, causing frost, condensate and repeated protective shutdowns. Live data isolated an abnormal BC Controller temperature sensor, which was later confirmed faulty and replaced.