Hi, I have an old furnace 20+ years old in the house I just moved into. The furnace will power on, the inducer motor spins and then the furnace ignites. The furnace will run until it gets to the temp on the thermostat then powers off like it should. It will power back on to heat back up and shut back off like normal. After 8-12 hours it will stop working and I'll get an error code flashing 3 blinking lights indicating the pressure switch is stuck open. If I power cycle the furnace it will work again for another 8-12 hours. Furnace is an Amana Air command hi efficiency 95 gas furnace. Model #: GUX070X30B Pressure Switch #: 20028403 - discontinued and I cannot find the part anywhere online. I cleaned out the condensate trap, double check the inducer/pressure switch tube. Exhaust looks to be clear. I do not see an external intake on this furnace. Here is a link to pictures of the pressure switch and model #. [url]https://imgur.com/gallery/Chrb5[/url] Not looking to replace the furnace this year. This pressure switch ([url]https://www.amazon.com/0130F00001P-Goodman-Furnace-Replacement-Pressure/dp/B00FJ99N6Y[/url]) has the same WC rating and 2 plug as mine, could I use it as a replacement? Any additional help would be much appreciated.

when the heat side kicks on, then the exhaust motor , then the electric spark. and then the gas is suppose come on and light. Well sometimes it does and sometimes it does not. I can reset it and it will usually start but that's hard to do when your sound asleep and get up to a cold house. Any ideas? I am thinking it maybe in the gas valve not opening up right. There are not codes on the mother board two green lights all the time.