Why Does Your Boiler Short Cycle? What Are The Reasons?

Boiler Short Cycle

Numerous facilities frequently use commercial boilers. These systems tend to last longer than other systems, produce steam or hot water for use in processes or for heating, and are generally energy-efficient. Boilers, however, do not last forever, just like any other system. Boilers can encounter unforeseen problems even with routine maintenance, which could cause delays in your facility’s operations. Boiler short cycling is a common issue that affects boilers. It lowers efficiency and may shorten the system’s lifespan. Continue reading to find out what boiler short cycling is, why it occurs frequently, and how to resolve the problem if your boiler is having any of these problems.

Reasons for short cycling

Oversized boiler

One of the most frequent reasons for boiler short cycles is an oversized boiler. If your boiler is larger than what is required to meet the demands of your facility, it is said to be oversized. Boilers may have been built larger than necessary at the outset, perhaps in expectation of unmet demands, or they may have grown larger as procedures became more streamlined or unnecessary.  Additionally, even if a boiler is appropriately sized for peak load, it may still need to cycle excessively during times when the facility experiences extremely low demand. An oversized boiler system can swiftly restore the heat (hot water or steam) that the system is consuming.  The boiler will cycle off as soon as it reaches the setpoint. Then, when the pressure and/or temperature drop, it will cycle back on.

Incorrect boiler set points

The performance of your boiler is significantly impacted by an inaccurate boiler pressure or temperature setpoint. The operator, limit, and, if equipped, modulating controls are probably some of the controls that regulate how your boiler responds to a load.  These are critical to the system’s intended operating pressure and each other’s setpoints. They may obstruct each other’s actions if they are too near to one another.  PID loop tuning is crucial for more complex controls because a poorly tuned control can result in brief cycling. 

Water flow issues

Water flow has a significant impact on the operation of hot water boilers.  In other words, the temperature rise across a boiler rises when flow through it is slowed down at a fixed firing rate (temperature leaving the boiler minus the temperature entering the boiler).  The boiler will cycle off if this rise pushes it over the setpoints on its control.  Consider it as though the system is unable to extract the energy that the boiler is delivering.  Numerous problems, including malfunctioning pump motors, problems with the pump’s “wet-end,” alterations to the system piping over time, and even inadvertent opening or closing of system valves, can be the cause of this.

Issues with burner tuning

Burner turndown is one factor that may be taken into account.  Turndown refers to a burner’s lowest firing rate. For instance, a minimum fire might be 20% of the maximum fire rate. The burner’s downward turndown may be limited by an improperly adjusted burner. For commercial boilers to operate as efficiently and last longer, they need to be properly maintained. Is it difficult for you to get your boiler to quit short cycling? Speak with the boiler room specialists at boilers Middlesbrough team to determine the best course of action.