When the thermostat calls for heat, the combustion air blower starts immediately. Next the spark ignition is energized, and the valve opens in the gas valve. The spark ignites the gas and the combustion process begins. However, the flame is only on between 3 to 10 seconds and kicks off.

Is this normal operation? It’s taken approximately 30 minutes to change the temperature in my garage by 1 degree on an 80,000 BTU unit.