We have a 2000 sf double wide mobile home that we bought new back in 1999. It came with a brand new Intertherm 3 ton unit. We live in South Carolina and our house sits in the middle of an old farmer's field, NO SHADE on the house from dawn till dusk.
We keep the thermostat set on 78* ALL the time. The unit will run ALL day, sometimes turning off, keeping the house between 78* and 80*. But on days like today that it was 90*+ degrees it run constinetly and the temperature in the house can get up to 83*. At night we don't have this problem it cuts on and off like it should. My question is, is this normal for an almost 10 year old unit or is there something wrong with it? If it is a problem, what does it need?