Integrated Boiler Control Time Delay Relay Combustion Coil Economizer Coil Burner (Flameholder) Exhaust Assembly Wall Plate Exhaust Terminal Intake Terminal Intake Terminal Thermal Cutout Intake Thermal Cutout Exhaust Thermal Cutout Gas Valve Ignitor Blower Assembly Circulator Pump Operating Control Safety High Limit Stack Switch Transformer Integrated Boiler Control Time Delay Relay Transformer Safety High Limit Gas Valve Operating Control Blower Assembly Stack Switch Exhaust Thermal Cutout Intake Thermal Cutout Combustion Coil Economizer Coil Burner (Flameholder) Exhaust Assembly Burner (Flameholder) Exhaust Assembly Combustion Coil