Concord 80 + gas furnace will not ignite burners.
Issue:
Draft blower turns on but no ignitition of gas burners and main blower does not turn on.

Investigation:
(1) LED is solid, no flshing
(2) Looked inside and saw 4 gas outlets that I think are the pilot lights and they are not lit.
(3) Looked at the pressure switch (is there only one?), I assume it's the pressure switch since it has a vacuum line connected to the draft blower. Vacuum line was attached and did not appear clogged.

Conclusion:
No clue. The LED should have been flashing if the system was not functioning normally.
Not sure if I've ID'ed the pilot light properly. I was expecting one pilot, not 4.
If the pilot light is out and the LED is solid, I'm suspecting the pilot light sensor is not working and giving a false reading. If so, what's keeping the gas valve from opening?

I'm guessing I just need to get the pilot lit, but I'm not sure I've ID'ed the pilot and I don't know how to light it. I was looking for a button on the gas valve that said Pilot, but it only has a knob that says ON/OFF/C.

Any suggestions would be appreaciated. (I did look online for a concord manual but did not find one.)

This is either a spark ignition or hot surface ignition system-there are no pilots to light. The four tubes you speak of are burners.

If it's a hot surface ignitor (has a large white ceramic base usually on right side of burner assembly with 2 wires coming out of the ceramic) do this...

Unplug the ignitor. Cycle furnace and check voltage across 2 female pins ignitor plugs into. If you get 110/120 volts then you have a bad hot surface ignitor. Replacement is easy enough on most units, acquiring them is another trick.

This is more than likely your problem.