What is the main function of a boiler feed pump?

The main function of a boiler feed pump is to supply water to the boiler. In a steam system, when water is converted into steam, it needs to be replenished to maintain the necessary water levels for efficient steam generation. The boiler feed pump is responsible for delivering this water from the system's condensate return or an external source back into the boiler. This ensures that the boiler operates efficiently and safely, as a proper water level is critical for preventing overheating and potential damage to the boiler.

Without the boiler feed pump properly functioning to supply water, the boiler could run low on water, which would impair its ability to produce steam, impact performance, and could even lead to dangerous conditions such as a dry fire situation. Each of the other options plays a role in steam system operation, but none fulfill the primary responsibility of ensuring that the boiler is continuously supplied with water, which is the core job of the feed pump.