Just replaced my board sensor but still get a sendor error. Readings over the board are 154 and 0 past the edge. I read someplace that if the head pressure is to low, it can also cause a board sensor error. My head pressure will only go up to 79 lbs. I believe the recommended pressure is 85 lbs. There are two shim washers on the crank handle now.

Without adding more shim washers is there another way to increase the head pressure?