I think some of you here are HVAC technicians or very interested so here is an update.
Their best technician came Friday Nov 17 to find out what is going on. Most if not all of the LED flashing codes indicated a low refrigerant level. So they decided to pull the charge and weigh it. It weighed 3.5lbs instead of 9,8lbs. So they (tech. phoned manager) concluded there is a leak. Pressurized with nitrogen to 600psig in attempt to find the leak(s). Hooked up a digital pressure gauge set Testo 550s. The pressure was dropping. Found a leaking flare fitting right at the outside unit. Checked all the coils and flare fittings at the inside units, using a sonic sniffer, and didn't find any leaks. Closed the isolation valves and hooked one tap on the Testo on the "machine" side and the other on the "house" side. This was a way to isolate where a leak might be if there is one remaining. Initially the machine side was dropping but we were in the afternoon and things were getting colder so not sure what is happening.
I'll attach graphs for comment.
Thanks.
