I am getting an F-20 error code. I have checked the hot and cold water flow and pressure and they are fine. What else could it be?
Answer Hello Frank,
You will want to check to make sure that the drain is not too far down in the standpipe causing a siphon effect. Check to make sure that the pressure hose is not kinked or clogged. Verify that there are no loose connections between the Control board, pressure switch and valve. If all checks ok then check to make sure that there is power getting to the valves. If no power replace Control board.