hugger5 Report post Posted March 15, 2014 I have a 1988 vintage Surburban furnace. I am not happy with airflow from this furnace. Looking for a possible more powerful blower. This is a 15000 btu furnace. It wants to cycle burner off before turning fan off. My thoughts were either a faulty high limit switch, or not enough airflow. Has anyone else had this condition? If so, what are my options. Share this post Link to post Share on other sites
dickandlois Report post Posted March 16, 2014 Hugger, They are built to do just that. The reason for the flame turning off before the blower stops, is to prevent the possibility of a fire. Should the flame stay on to long with the blower off, the stainless steel heat exchanger will get red hot. That much heat in the confined space surrounding the furnace, would be a fire in the making at some point in time. RV furnaces are built to provide maximum heat at the lowest weight. That is also the reason the blower must start before the gas valve is allowed to open! Rich. Share this post Link to post Share on other sites
kaypsmith Report post Posted March 16, 2014 Cycle the burner off before burner is pretty much standard in all units that I have been around. I don't think that it would be wise in the other direction because one would not want excess heat left in the chamber. One should consider if the heat has met the correct temperature that was set on the thermostat before turning off. All that said, you might have a faulty unit, but without more info., it is hard to tell. Share this post Link to post Share on other sites
kaypsmith Report post Posted March 16, 2014 Rich replied while I was typing, with the correct answer. Share this post Link to post Share on other sites
