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If this is the first time this year that your furnace has got the call for heat. It might be something as simple as a restriction in the air tubing going from the inducer motor housing to the pressure switch, something as small as a spider or a spider egg. If there is a restriction the pressure switch will not make. If that switch does not make it will not allow the ignition process to occur. There could also be a restriction in the flu. Some furnaces this will be PVC. If there was a dead bird, a nest, or anything blocking the flu. That pressure switch will not make. The pressure switch is a safety in place to prevent your furnace from firing up. Turn off power to your furnace and if you are capable of removing the upper panel on the front of your furnace. Look for a rubber tube a little bigger than a straw. It will be hooked to a round plastic switch, a little smaller than a can of chew. Unhook the vent tube and blow through it and put it back on. Then remove the exhaust from the top of the furnace. Now turn the power back on. If it fires up immediately turn the furnace off and put the exhaust back on. Then turn the power back on. If it doesn't start your flu is restricted.
Hope this will get you going, I am punching out for tonight
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At this point the negative pressure will need to be measured with a manometer to determine if it is out of specs,
the pressure switch may be defective and not sensitive enough to close.
You could try replacing pressure switch or have a technician take readings of negative pressure.
Sorry you are having trouble getting it going but after all the checks we covered, it should work, unless that we are dealing with a defective pressure switch, it may be a indication of a more serious problem such as a cracked heat exchanger ...