The Challenge
The building was experiencing persistent boiler frost alarms and continuous heating demand. In response, parts of the system had been manually overridden and plant isolated to prevent nuisance alarms and unnecessary operation.
While these interventions addressed the symptoms, they prevented the building’s automation systems from operating as designed and obscured the true source of the problem.
Our Investigation
Rather than focusing solely on the boiler alarms, we traced the source of the heating demand.
We discovered:
- An actuator serving the Atrium AHU had failed resulting in a genuine heating demand not being satisfied.
- This demand was holding the heating system in operation despite no meaningful heat being delivered to the space.
- Boilers had subsequently been isolated locally, preventing normal operation and creating secondary frost alarms.
- Control logic was causing multiple pump sets to run unnecessarily, increasing energy consumption without benefit.
The Root Cause
The boiler alarms were not the problem.
The root cause was a failed actuator combined with manual interventions that had gradually moved the system away from its intended operating strategy.
As often happens in complex buildings, engineers had responded to individual symptoms rather than addressing the underlying cause.
The Outcome
- Root cause identified and isolated.
- Unnecessary plant operation reduced.
- Energy consumption reduced through improved control logic.
- Nuisance alarms minimised.
- Building automation returned closer to its intended operating strategy.
Key Lesson
Building automation systems are designed to optimise performance and energy use. When faults are addressed through manual intervention rather than root-cause resolution, the result is often a building that consumes more energy, generates more alarms, and performs less effectively.
In this instance, what appeared to be a boiler problem turned out to be a control-system problem. By understanding the entire system rather than individual components, we were able to improve reliability, reduce energy waste, and establish a clear path to permanent resolution.
Buildings underperform when people manage symptoms. Buildings performance is maintained when people understand its systems.