In San Diego non-summer heat waves usually last only a few days, so by the time the air conditioner repairman comes gets there the weather has cooled, you are no longer using the air conditioner, and you don’t know whether the repair has been effective or not.
We had one of our brief warm spells in February and my unit (which is still under warranty) did not keep the house cool, so I called for service. The guy said it was low on refrigerant and added five pounds along with some "stop leak," which he said would fix it.
I did not use it again until April, at which point it did not cool the house properly, so I called for service again. The guy said that the unit was overcharged and removed five pounds of refrigerant, which he said would solve the problem. The weather dropped to a high of 68 degrees, so we’ll have to see, but one has wonder.
Let’s say you have a machine which is running lopsided. The repairman says, “Oh, it needs a frammis,” and puts a frammis on it. The next time you go to run the machine, it is running lopsided again and a different repairman says, “Oh, the problem is that frammis. That shouldn’t be there,” takes the frammis off and proclaims it fixed.
The next time you go to run the machine, how is it going to run? Lopsided is how it’s going to run. It is now in the same state that it was in before the frammis was added, and it was running lopsided at that point. Why is adding and then removing a frammis going to make it run any better?
Why is adding five pounds of refrigerant and then removing it going to make my air conditioner work any better? The service company has not explained that. To give credit where it is due, at least they have not charged me any money for not fixing my air conditioner.