HVAC Questions? Ask an HVAC Expert for Answers ASAP
so when you bypass the pressure switch the furnace does light and work fine or doesn't?
Find the red wires that go into the plug on the control board. Cut them about 6 " away from the control board plug so that you leave yourself enough room to reconnect them with wire nuts when we are done. Take the two red wires coming out of the plug and wire nut them together so that it forms a loop going out of the plug then right back into the plug.
Now unplug the yellow and orange wire going to the pressure switch and start up the furnace. once the inducer draft motor starts up hook/jump this yellow and orange wire together and keep it together the whole time. Tell me if the hot surface igniter glows this time.
I have the diagram you gave me and it shows the two blue wires connecting the pressure switch, but this diagram shows a smart valve with 3 plugs in it and the pressure switch and limits all tie into the smart valve (gas valve) is this correct?
also what type of vent pipe comes off the furnace PVC or metal