Gas Furnaces Re: L4064B Fan & Limit Switch The L4064B controls the on and off operation of the heating unit’s fan motor and provides high limit control of the main burner. It is suitable for all types of forced air heating systems. The L4064B’s bimetal sensing element turns fan on and...

Gas Furnace Re: Burners Cycling Off / Burners Won't Stay On The furnace burners fire and run for several minutes, then the burners shut off and the furnace goes through another ignition sequence. These furnaces use either a Robertshaw SP735 or White-Rodgers 50E47 hot-surface ignition...

Gas Furnaces Re: Furnace Won't Come On / No Heat This condition is generally reported two different ways by the customer: "The furnace won't do anything." - Indicating that there is no activity from the furnace on a call for heat. "The furnace makes a noise, but it never blows-out hot...

Gas Furnace Re: Burners Fire then Shut Off The furnace goes through a normal ignition sequence, but several seconds after ignition the burners shut off. Qty Possible Causes: 3 Dirty flame sensor Bad Ignition Control Incomplete Ignition Pressure...

Gas Furnace Re: Lockout / Sometimes Doesn't Heat Customer reports that the furnace sometimes stops working. They can get it to work again by turning the thermostat or power off and back on. Small Control Most of these gas furnaces, 80 & 90%, use a White-Rodgers or Robertshaw...