Expansion Vessels

This part is in the boiler to protect the boiler from excessive surges and that the pressure within the boiler operates within safe parameters normally between 1 to 2.5 bar. The expansion vessel is filled half full of air and half full of water. The most common issues customer’s encounter when the expansion vessel is faulty is the boiler pressure builds to 3 bar and hot water starts to drip through the pressure relief valve and outside via the discharge pipe. When the boiler then cools down the pressure in the boiler falls to 0 bar and won’t fire up. The customer then has to fill the boiler back up by using the filling loop normally located below the boiler. Once the pressure in the boiler is back at 1 -1.5bar the boiler will start to work again.