How do you size an expansion vessel?
Expansion volume The expansion volume is calculated as follows: expansion volume = water capacity x increase in volume at average heating temperature. Example: heating temperature 90/70 °C (average 80 °C) = 2.89%. Safety factor We recommend including a margin of 25% when calculating the expansion volume.
Can you over Pressurise an expansion vessel?
Boiler pressure is controlled by the expansion vessel, the balance of air versus water in your central heating system. Too much air could result in an over pressurised system, this could also result in water coming out from the pressure relief valve.
How big should my expansion tank be?
In fact, if unsure that your expansion tank will be able to safely accommodate your system, it is common practice to choose an expansion tank that is one size larger than the required size. As a general rule of thumb with expansion tanks, it is better to oversize than to undersize.
What is a white expansion vessel for?
Expansion tanks are also known as expansion vessels and are used to protect closed water heating systems and domestic hot water systems from excessive pressure. As the water heats up the pressure can increase by 4.5% so they are a very important part of any sealed system.
What happens if expansion vessel is too small?
An undersized vessel can cause big pressure swings too but those swings would have been present since installation. If, however, you’ve recently extended your central heating system by several radiators, the existing expansion vessel could be too small and this would also cause larger swings in pressure.
Can a faulty expansion vessel cause pressure loss?
3-You have a faulty expansion vessel You have a faulty expansion vessel- This means your boiler pressure will exceed 3 bar during the heating up process. When the system cools down you will find the water lost will now show on the pressure gauge as a significant drop.