What should the pH in hot water boilers generally be?

The pH level in hot water boilers is crucial for preventing corrosion and ensuring the longevity of the system. Generally, a pH range of 8 to 8.5 is considered optimal for hot water boilers. This slightly alkaline environment helps to minimize the solubility of common corrosion products and maintain a protective layer on metal surfaces, thereby reducing the risk of pitting and other forms of corrosion.

If the pH were to drop below this range, it could lead to acidic conditions that promote corrosion, especially in systems that rely on ferrous materials. Conversely, a pH much higher than 8.5 might lead to scaling and other issues associated with overly alkaline water. Therefore, maintaining a pH between 8 and 8.5 strikes a balance that protects the system effectively.

This pH range is commonly recommended in various industry standards and guidelines for maintaining safe and efficient operation in hot water boiler systems.