I have a Concord 80 Plus Gas Furnace. I had a friend look at it when it was blowing out cold air when turned on, and he said the burners were not kicking on for some reason. When taking a few things apart, he determined that it was due to a faulty pressure switch. When the two wires that attach to the pressure switch are put together the burners kick on. But they have to be reattached each time to keep it running when it shuts off. I want to make sure that the pressure switch is the problem before purchasing a new one?

Check for a plugged up line going to the pressure switch. If not plugged up it usually means the switch is bad. Is your combustion air blowr working?

All your doing when you touch the two wires together is bypassing a safety switch. You can blow and suck lightly on the small rubber line going to the pressure switch(disconnect from collector box). You should here it click when you do this. Hook the line back up to the collector box and blow on the line once more to make sure the collector box is clear. If you have a restriction in furnace vent pipe that will keep it from closing.