What is the primary function of a draft control in a boiler?

What is the primary function of a draft control in a boiler?

• A. Regulates water temperature
• B. Regulates the draft to ensure proper combustion air
• C. Controls pressure
• D. Balances flow between zones

Answer: (B)

Regulating the amount of air that enters the combustion chamber is what a draft control does. It keeps the right fuel–air mix so the burner burns efficiently and consistently. When the draft is properly controlled, the flame stays steady, fuel is burned cleanly, and heat is produced without wasting energy or creating excessive smoke or emissions. It also helps prevent backdrafts and adjusts for changes in venting or weather that could otherwise push too much or too little air through the burner. This function isn’t about water temperature, which is controlled by feedwater and burner settings, nor is it a direct control of system pressure. It also doesn’t handle balancing flow between different heating zones.

Regulating the amount of air that enters the combustion chamber is what a draft control does. It keeps the right fuel–air mix so the burner burns efficiently and consistently. When the draft is properly controlled, the flame stays steady, fuel is burned cleanly, and heat is produced without wasting energy or creating excessive smoke or emissions. It also helps prevent backdrafts and adjusts for changes in venting or weather that could otherwise push too much or too little air through the burner.

This function isn’t about water temperature, which is controlled by feedwater and burner settings, nor is it a direct control of system pressure. It also doesn’t handle balancing flow between different heating zones.