Why is my heating or cooling system not responding to the thermostat?

First, verify the SYSTEM button is set to the correct mode (Heat or Cool) and that the temperature setting is higher than the indoor temperature for heat, or lower for cool. Also check that the circuit breaker is not tripped, the power switch at the heating and cooling system is on, and the furnace door is securely closed. If none of these resolve the issue, wait 5 minutes for the system to respond. (Page 19)