Before going any further, perform your annual cleaning. Clean your venting, pull out your exhaust fan and clean the blades inside the housing. Remove your Heat Shields (metal plates surrounding your fire in the burn chamber) and clean the air passage ways. Finally, inspect all gaskets and replace if needed. If that doesn't work, the problem could either be with the pressure switch or the exhaust fan. Check the pressure switch. See if the wires leading to the pressure switch are loose. The pressure switch tube could also be plugged, broken or loosened. If the stove still isn't running, check to see if the exhaust fan is working. If not, you could have an exhaust fan failure. Please contact your retail store where you purchased the unit for more help.