What does the Furnace Pressure Switch monitor in a boiler?

• A. Water level in the tank
• B. Temperature of the steam
• C. Pressure in the furnace
• D. Electrical current for the burners

Answer: (C)

The Furnace Pressure Switch is designed to monitor the pressure within the furnace of a boiler. Its primary function is to ensure safe operation by verifying that the pressure is within specified limits. This switch detects whether the pressure in the combustion chamber is appropriate for the safe and efficient operation of the combustion process. If the pressure deviates outside safe parameters—either too high or too low—the switch can trigger alarms, shut down the system, or prevent burner operation to protect the equipment and ensure safety.

Understanding the correct monitoring of furnace pressure is critical, as it directly impacts combustion efficiency and can prevent dangerous situations such as backdraft or inadequate combustion airflow. Monitoring pressure is essential for maintaining the desired conditions for burning fuel effectively, which directly influences the overall performance and safety of the boiler system.