Firstly I dont think you can rely on the accuracy of the manometer on domestic machines. That aside, if you keep getting steam coming out of the group after flusing for a minute then it sounds like it is running too hot.
Is there any chance you have the steam switch on whilst you are brewing? If not I would be taking it back to the store. If you bought the machine from the online seller which comes up under a google search ...... good luck getting good service.