Ask 'Dr. Spa' Q & A Message Board

I have a 1999 Blue Ridge 6 person spa 240v. It was recently given to me, but it needed a new heater. I got a replacement heater same type and same model number. The circulation pump was replaced a year ago. I have the Spa wired directly into a 50 amp GFI breaker. When I switch the breaker on the circulation pump runs and when I push the buttons for the Jets, blower and lights they all work, all the lights come on the top control panel except the digital lights do not work, nor does the water heat up. I have searched and searched, but cannot find the pressure switch for the heater. Can some on please tell me where it is at? Also how does the high limit switch work? Mine I can turn, but it doesn't seam to do anything.