About two weeks ago I noticed that it was getting warm in my home occasionally. especially when I ccoked and when i did laundry. The a/c was not keeping up with the setting on the thermostat. It would do it every once in awhile and then it would work regularly. Last night I noticed it happening again but this time it has not fixed itself. It stayed at a consistant 81 but had the thermostat at 76. We usually keep it at 78 and it stays on that temp so dont know whats going on? Unit is only over three years old. help!!! My husband is pretty handy but need some advice as to what we are dealing withj.