How long is the pre-purge interval on a low pressure boiler?

The pre-purge interval for a low-pressure boiler is typically set to 90 seconds. This period is crucial for ensuring safety and efficiency before the burner is activated. During the pre-purge phase, the system clears out any potentially hazardous gas from the combustion chamber, thereby reducing the risk of explosion or other safety hazards associated with unburned fuel.

Having a standard duration of 90 seconds allows for an adequate amount of time to ensure that any accumulated gas is effectively vented out, thus providing a safer startup process for the boiler. Maintaining this interval is essential for compliance with safety regulations and best practices in boiler operation, ensuring that the system runs efficiently and safely from the moment it begins operation.