If an AC guy checks a system and finds it 100% out of refrigerant, what is the correct next step?

Question

I'm doing a sort of feasibility follow up regarding a visit from our neighborhood AC repair person. He checked our system and found it was completely out of refrigerant. He added 7.5 lbs.

I'll add more to this after I see some answers, but I wanted to know if he did the right thing or if he should have done more. I was out of refrigerant, so he filled it back up. Seems open and shut but...

I would love your thoughts.

Edit 1

Wow! I wasn't expecting this to get so much traffic. In any case, you guys did a great job answering my question. The full story is that, as I said, my AC stopped cooling, but the unit was running fine as far as I knew. I called our neighborhood guy that does a lot of jobs for our area and has good word of mouth feedback on NextDoor. He saw my freon was out and filled it back up. 7.5 lbs of freon. A month later, it stops cooling again. I have him come out and look and he says the freon is down to half. The unit itself is a 1999 unit so it really is about time to replace the thing. Over the past several years I had spend at least $600 annually on maintenance so this should pay for itself in a few years. I had 3 people in total review the unit and 2 of them identified an issue with the indoor unit (condenser coil or something...I don't know the exact terminology). It was only after all of this that I felt like the first guy should have done more investigating the prior month, especially with the freon being slap dry.

In the end I replaced an 8 SEER unit for a 14.5 SEER unit. I'm hoping that will save me a good bit on my electric bill. I'm looking into other ways I can save on that, but that's a question for another thread.

Thanks!

Answer 1

If the system still had pressure you could add the correct amount of refrigerant and get the system running again. However the correct fix should be to find the leak, fix the leak, add suction and discharge filter driers, evacuate the system, then recharge with refrigerant. Just recharging with refrigerant guarantees the service company another service call to again recharge the system, since it will again leak out. I would explain your options and let you decide. My unit is 19 years old and has no leaks and has never had to have refrigerant added. What a great cost savings for me.

Answer 2

I had an AC guy say "your system is completely empty", and he had to schedule a follow-up.

Then, the next day, the same guy came out and said that he figured it out over-night! He had to go away from the problem and then it came to him over dinner: I have an old three-position valve on that head unit, and the three positions are: Run, Off, and Test. Most newer valves only have Run and Off (and if they need to Test it they Test it while it's Run). On this older setup, if you have it in Run and try to Test it with pressure gear, it reads flat zero.

So the solution was to twist this three-position valve to the right position for testing. Then he found that my system had coolant, and the problem was really a fuze! Now I know to warn all AC guys about this three-position valve.