I have a hayward H250 FD, lo nox that wont stay lit. On this board it was suggested to check my flame sensor. Problem is the screw holding it in place will not turn. Don't know if its rusted or what, but a screw driver wont do it. I grabbed a socket and thought that would do it, but the screw head is too close to the sensor itself for the socket to seat properly. Any one own this model and have experience with this? The location of this part could not be located in a worse spot.