I arrived to do a scheduled maintenance agreement on a American standard gas furnace Technician arrived and completed tune up checklist for safety issues, combustion, and efficiency. Found the furnace was tripping in high limit at 138 degrees when the rating in the hi limit switch is factory set for 180 degrees. Diagnosed bad high limit switch, needs replaced or furnace will be short cycling and shutting off after only a few minutes of running then restart. Customer would like to hold off on the repair at this time
