Air Conditioner
J asked:

We have an air conditioner that is supposed to cool both the second and third floor of our house.

Unfortunately the air conditioner inadvertainly starts to heat our house sometimes when its supposed to be cooling it.

The only way to get it to work right is to turn off the air conditioner and the electricity (fuse) from the circuit-breaker box.

Any ideas what might be causing this? How can I fix this?
It looks fairly old. Have only been living in this home for about 3 years or so. Don’t know too much about it other than the brand name: Trane.