Feenstra Boiler - Low Pressure - Expansion Vessel Failure

A common cause of low pressure in Feenstra boilers is a faulty expansion vessel. The expansion vessel accommodates the expansion of water as it heats up, maintaining stable pressure within the system. If the vessel's diaphragm is ruptured or the vessel is not pre-charged correctly, it will not be able to perform this function, leading to pressure drops, especially when the boiler is heating up.

Symptoms of a failing expansion vessel:

• Frequent need to repressurise the system
• Pressure fluctuations when the boiler is heating
• Water leaking from the expansion vessel (if diaphragm is ruptured)
• Radiators cold at the top