Our central unit is about 10 years old. For the last 2-3 years our air conditioning unit has come on and ran but will shut off occasionally. Sometimes once sometimes it may do it numerous times during the cycle. We have contacted an Heat & Air service co but they say without them seeing the code when it does it they can not help us. Our unit is in our attic and nobody wants to sit up there and watch it for the code and we also don't want to pay someone to sit and wait for it to kick off. It may do this more often during higher temps or maybe humidity. Not really sure.