View Full Version : Flash code 3
popisr
Oct 20, 2011, 05:31 PM
Installed cnt 03797 board now I get code 3 pressure switch problem instructions call for disconnect pressure wires what could be problem bad board
T-Top
Oct 20, 2011, 07:22 PM
Restricted vent or vent motor not working. Vent pressure switch stuck open or closed.
popisr
Oct 21, 2011, 08:11 AM
Vent motor is working pressure switch is not needed with new cnt 03797 control instruction called for pressure switch be disconnected
T-Top
Oct 21, 2011, 03:09 PM
I can kind of see what your saying. Not knowing make and model of the furnace only slows our process. If your system is inducer draft(vent motor) It will have a pressure switch, vacuum switch or centrifugal switch. One of the above will have to close a circuit to prove the motor is running and the vent is clear for it to light.