The first technician that came over thought the problem was the condenser capacitor, which was old, I replaced that but didn't fix the problem. All the components were running, including the compressor and both fans inside and outside but no cooling. He said the refrigerant pressure was OK but...
The second guy said the refrigerant was completely gone (which means the first guy was lying and will never call him again) and thought the leak must be withing the evaporator coils based on a known problem with Lennox that even has a class action lawsuit. But that was a red flag to me because he just wanted to replace the coils on a mere suspicion and no definitive leak find. So I won't be calling that guy anymore either.
I brought a third guy who did a nitrogen test but could not find any leaks. We sprayed all the brazed connections with microleak detection fluid, no bubbles anywhere, no hissing noise, no nothing. Both on the condenser side as well as in the coils. He said basically just recharge the system. Here is the pressure gauge readings that held for like 45 min.
I have enough leftover 410a in a tank from last time the compressor was changed, so it would not be expensive to just wing it and recharge to see what happens. But the test results are not consistent with the incident of losing all the refrigerant in the system. So is there anything else that could explain this mysterious loss of refrigerant?
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