Which of the following indicates a problem with a boiler's performance?

Frequent pressure fluctuations signal a potential problem with a boiler's performance. In a properly functioning boiler, the pressure should remain relatively stable, allowing for efficient heating and optimal operation. When fluctuations occur, it may indicate underlying issues such as inconsistent water supply, malfunctioning pressure relief valves, or problems within the boiler’s control systems. Such fluctuations can lead to inefficiency, increased wear and tear on the system, and may even result in safety concerns if not addressed promptly.

On the other hand, consistent temperature, efficient fuel consumption, and stable flame are indicators of a well-functioning boiler. These traits suggest that the boiler is operating within its designed parameters, providing reliable heating and effectively using fuel. Therefore, identifying frequent pressure fluctuations is crucial for maintaining safe and efficient boiler operation and reflecting a problem that needs investigation.