Late last summer, I felt my central AC was not cooling adequately. The air from the registers was only 10-13 degrees F below room temp and the suction line back to the condenser unit was about room temp (normally it is cold). I had a tech come out and check it. He found it was low on R22 and put some in. Cools great.
Now its cooling season again and the unit is behaving as if it is low on R22. I found this odd since it went for 10 years since last charge up.
I remember that the service port cap, the tech put on was a silvery color, not the brownish colored original one. I figured he dropped the original one and lost it in the grass and put on a spare. I never questioned this. Now, I noticed an oil stain around service ports and suspect it is leaking there. I removed the cap and notice a slight hiss from the low side service port. I also notice the cap the repairman replaced has no rubber grommet to help seal the valve.
While the HVAC service industry is typically honest, It is hard to believe I wasn't somehow duped with the cap switch.
Is this one of their common tricks?
I'm going to call a different company to fill it again and install a new cap.
John