Replace the gas orifice and gas burner.

Replacement should include

• checking the orifice for each brand name and size (British thermal units [BTU]) furnace
• identifying the orifices by type (liquid propane [LP] or natural gas system)
• replacing a gas burner (LP or natural gas system), following manufacturer guidelines.

Process/Skill Questions:

• What type of gas orifice is standard on new furnaces?
• What is the gas pressure setting for the LP orifice?
• What is the gas pressure setting for the natural gas orifice?
• What causes burner failure?
• Why are burners tapered?