We had a hot week a couple weeks back and at some point my mom noticed the a/c wasn't working very well anymore. She made the call for service on their 14 year old Bryant, they said they would come out the next week. Turns out it was a bad fan motor in the condenser. My dad replaced that himself to get it working again. Since they already had the appointment they decided to keep it, even though the system was working, and use it to get a check up.
Here's the scary part. I asked my mom what the tech said about their system. She said they told her it was low on charge and they had to add freon. I asked my mom "where did it go"? These guys apparently convinced my parents that over time the freon leaks out through "pores" in the metal. I said b.s., if you're low on charge it went somewhere, you have a leak and the leak needs to be fixed.
One more thing they said that scared me was that the system was "25% low on charge". They must have vacuumed the system down and weighed it right? I doubt it. You can't know how much volume a given system has and then derive a percentage can you? Aren't they all going to be different due to line set sizes and lengths? And if it was really 25% low on charge, wouldn't that have caused other problems like coil freeze ups, as well as possibly slugged the compressor?
I couldn't convince my parents they recieved poor service. They think it is normal for charge to just disappear over time even though I told them it a system is done right it should never need freon to be added.