When you jumper pressure switch, you need to wait until the inducer motor starts and reaches full speed and then put your jumper across it. Then your ignitor will glow, then burners should light. If ignitor glows and burners do not light, you may have faulty gas valve or bad control which is not sending 27volts to the valve. Pull wires from gas valve and start the whole cycle over with a volt meter across both wires set on ac volts, then wait for ignitor to glow, at this time there should be 27 volts read on meter. Be patient while waiting for 27v it takes several sec. If voltage is noted, then you more than likely have a faulty valve, make sure to re connwct wires and cycle again. If no voltage to valve, then control board is culprit, check 12 pin connector for secure connection. Hope this helps