When should the boiler vent be open?

The boiler vent should be open when filling the boiler with water and before cutting the boiler online. This is crucial to prevent the buildup of pressure inside the boiler while water is being added. Opening the vent allows air to escape and ensures that the boiler can fill properly without creating a vacuum or causing water hammer.

Maintaining proper venting during this process helps in achieving safe operation, as any trapped air can lead to inconsistent water levels and operational issues once the boiler is brought online. Being able to effectively vent air while filling the boiler is essential for ensuring the system operates efficiently and safely once in use.