I have a 8 year old furnace. It is Amana 80 SV After My furnace is flood with water , the central air still works fine , but when I turn on the heat , it is not working , no flame .... The led trouble code is 3 blinks = "Pressure switch stuck " is Pressure switch is bad ? do I need to replace it ? I take out the end of the hose and blow it , I hear click from pressure switch , the hose is not clogged . Please advice me . Thanks.