You just finished Installing your Aurum 16 ,Aurum 18 ,Aurum 22 you plug in your disconnect, flip your breaker on and power on the remote. You're expecting your unit to be blowing cold air as you have it set to cooling. Its not and all of a sudden the unit goes into Fo and only the fan runs. if you check the troubleshooting app fo is listed as gathering refrigerant. In my experience as tech support I found that in most cases this error code was a strong indicator that the contractor, either did not vacuum down to 500 microns or did not vacuum at all. in some cases the contractor forgot to open the low side and high side valves.
A good way to troubleshoot this issue is by pressure on your low side gauges upon initial connection you should receive a reading of 150-220 psi, that is of course with the compressor off. once your compressor kicks on if you see a rapid decline in pressure that means 1 of 2 things. 1. your valves are closed ,2.there is a restriction if your pressure stabilizes in the appropriate psi, your unit is telling you a vacuum wasn't completed. in which the refrigerant should be recovered, the unit should be vacuumed and the unit should be recharged following a evacuation to 500 microns or below.
article by: Kathem Muhammad (Tech Support)