My air conditioner continues to run but is not cooling the house. What could be the problem?

There could be many different problems but I would check the air filter to be sure it is clean and that all the registers and return air openings are open and not closed off. In some areas of the USA are suffering with unusual high temperatures. If your unit will cool the house 20 degrees or so from the outside temperature you are doing OK. In other words if it is 100 outside and the temp inside is holding at 80 then your unit is performing. If this is not the case then you might need to place a call for on site service so a tech can check your system. It is a good possibility your outside unit needs to be cleaned and serviced.