Furnace repair. Upon arrival, customer said the system would work all the way up to the gas valve opening up. I tested/cycled unit 4 times and could not get the system to do the intermittent ignition fail, however I replaced gas valve with new/same 2stage gas valve rated for this exact furnace. Tested/cycled unit 3 times and waited long enough to have system go into 2nd stage heating. System is operating and heating as it should be at this time. No charge to customer due to recent no heat call.