Which statement best describes boiler cycling?

Which statement best describes boiler cycling?

• A. The boiler maintains a constant output regardless of demand
• B. The boiler alternates between meeting load and shutting down
• C. The boiler only starts once per day
• D. The boiler cycles by modulating to maintain exact temp

Answer: (B)

Boiler cycling is the on/off firing pattern where the boiler turns on to meet heating demand and then shuts off when the space reaches the setpoint, repeating as needed. This alternating behavior—fire to meet load, then stop until the temperature drops again—best describes cycling. It’s different from running constantly at a fixed output or continuously modulating to maintain an exact temperature, both of which would not be on/off cycles. The option that matches cycling captures this repeated on/off action as demand rises and falls.

Boiler cycling is the on/off firing pattern where the boiler turns on to meet heating demand and then shuts off when the space reaches the setpoint, repeating as needed. This alternating behavior—fire to meet load, then stop until the temperature drops again—best describes cycling. It’s different from running constantly at a fixed output or continuously modulating to maintain an exact temperature, both of which would not be on/off cycles. The option that matches cycling captures this repeated on/off action as demand rises and falls.