Hello,
I have a York (forced air) gas furnace that's 9 years old. Every winter it seems like I have to replace the pressure switch ( round switch with 2 connections & air hose). I hear the blower come on, burners ignite and then within a few seconds they go off with the red light flashing 6 times. Blower continues to blow cold air and stops. Checked the air hose & it's connection hole for blockage and they are clear.

I have repalced the pressure switch last year because of the same problem, it seems like it works for a year and then it goes bad. I appreciate any suggestions,troubleshooting tips or advise.

Thank you very much in advance!

6= lockout caused by pressure switch.

If the part is bad it is bad. Could be moisture is somehow causing the contacts to fail but on this end I know of no problem with the system in regards to pressure switches unless the ones you are buying are not the correct ones for a York. Pressures switches have different pressure rates and not using the correct one could cause permature failure.

If the unit starts but then drops out then the switch is apparently closing or else you would never get ignition. If it is opening up after ignition then your inducer could be in the process of failing. Are you sure that it is 6 flashes? The symptoms you are describing sound as if your flame sensor is dirty.

I have the same problem replaced the sensor and still does the same thing? Six red lights is bad flam sensor or low gas pressure I don't have either one?