Where is the furnace reset button located?

Where the furnace reset button is located depends on furnace brand and model, but generally it is on the burner compartment and is a small red or yellow button that pops out when tripped. For most gas furnaces like Trane S9V2, Carrier Infinity, and Lennox EL296V, the reset button is actually the rollout switch or high limit switch located inside the burner compartment behind the lower front panel. To find it, turn off power to furnace at switch on side, remove lower front panel by lifting up, look for small device with red button about size of quarter near burner assembly, usually mounted on burner box or on heat exchanger limit. For oil furnaces, reset button is more obvious: it is red button on primary control box mounted on burner motor, press once. For high efficiency gas furnace with 90 percent AFUE and above, there is no dedicated reset button like oil furnace, but there is an on-off power switch on side of furnace that acts as reset: turn off for 30 seconds then on. Also circuit breaker at panel serves as reset. If your furnace has error and will not start, pressing rollout reset may allow one restart, but if it trips again, do not keep resetting as it indicates serious problem like cracked heat exchanger or blocked flue that can cause carbon monoxide leak, call technician immediately. Always check filter first as dirty filter causes limit to trip.