Performed furnace clean and tune; customer stated he had issues this past weekend furnace would not ignite, I cycled the furnace on without any issues sounds like we had a pressure switch stuck open, I ohmed out the igniter which did test weak, checked gas pressures, as well as performed a combustion test verifying no CO in the airstream. This system is currently running at this time but future failure is expected this system is 18+ years old due to the age, condition, and cost to repair I highly recommend replacement of the furnace. Eric would like quotes for a new Furnace/AC second opinion scheduled with Jamie L today at 10. Job complete