I am getting the pressure switch blockage and the three red light code. Replaced the pressure switch and still does not work

The inducer motor would run until the heat shut off .if pressure switch is closed and all other safety switches close your furnace should fire up

The pressure switch is a pressure sensing device to ensure the system is operating within the parameters for which it was designed. The pressure switch on the positive pressure side of the combustion air fan when tripped indicates a flu blockage which will limit the amount of flu gasses passing through the heat exchanger. I would suggest checking the flu for a blockage and if there is a second pipe (combustion air), you should check it also as with either blocked, the proper operation of the pressure switches is in jeopardy.

You cannot bypass the pressure switches because the algorithym in the control module will see that the pressure switch is in the wrong position at the moment a call for heat was initiated.

If there are no flue blockages apparent but you find that there is no screen on the end of the flu pipe or pipes, you may still have a blockage in the form of a dead bird. They like to roost inside the openings of the pvc pipes for warmth, then die of carbon monoxide poisoning and block the pipe. Sometimes they even make their way the full horizontal length and die at an elbow and fall directly on top of the flu opening on top of the furnace. I have had to make numerous cuts to locate blockages before.

jump out pressure switch see if it lights check hose to pressure switch see if they are split or connections are not good ,cut off ends and put back on presure switch.

That blinking 3 times is indicating a pressure switch problem. Try checking for water or a blockage in any of the hoses going to the pressure switch or condensate drain. Check the air intake and exhaust pipe for any blockage including any saggs that may hold water. Make sure condensate drain or pump is working. If you get a glow from the igniter, there may be a blockage in the gas valve or piping.

Hello, a 3 flash on a circuit board means that a pressure switch is open, this could be due to a blockage in the flue pipe or the small tubing that goes from the inducer to the pressure switch is loose, leaking, or is blocked. You can try taking the tubing out and checking if there is anything in it blocking the pressure between the pressure switch and inducer motor and then attaching back on and make sure it's secure and tight. If that does not work that the switch itself is bad and must be replaced.

It may look like a small round disc and is connected to the inducer or exhaust fan by one or two small hoses. Make sure the hoses are free of any blockage, the air filter is clean, any hoses for the condensate drain is free of any water blockage, make sure your condensate pump is working (if you have one) or that the main water drain is not obstructed. Also inspect the fresh air inlet pipe and exhaust pipe for any sags where water can collect or any other blockage. If you find no blockage anywhere, replace the pressure switch. You may even have to remove the inducer fan to inspect for blockage. If you remove the hoses off the pressure switch, you should feel a small vacuume being produced that closes the pressure switch. If you feel nothing, you have a bad inducer.

Good Luck.

The 3 flashes is an error code. Most likely you have either a vent blockage, the inducer motor is not spinning fast enough to draw a vacuum on the pressure switch, you have a bad pressure switch or a blockage in the hose going to the pressure switch. You can **** lightly on the hose going to the pressure switch to close it or you can jump it out to test it.

Pressure switch error code, Check the air filter for blockage, check the vent pipes for blockage or water, make sure the condensate drains are working and that there is no water in the hose(s) that go to the pressure switch(s).

Pressure switch error code, check air filter, condenstate drain and hoses, check for vent blockage, check for low spots in the venting holding water.

Make sure that lamp door is fixed securely and pressing lamp door switch as 3 times blinks shows lamp door switch is not On.