Why isn't my heating or cooling system responding?

Several steps can resolve this issue: first, press Menu and Mode to set the system to Heat (ensure temperature is higher than inside temperature) or Cool (ensure temperature is lower than inside temperature). Check the circuit breaker and reset if necessary, verify the power switch at the heating/cooling system is on, ensure the furnace door is closed securely, and wait 5 minutes for the system to respond. If the system still doesn't work, check your System Setup Options 200 or 218 to ensure they match your equipment.