Worcester Bosch Boilers and hard water

When it comes to your boiler, good maintenance is the key to a long lifespan. This means being aware of any changes in your boiler behaviour, or in your central heating system. As leading Worcester Bosch boiler experts, we regularly tackle boilers that are suffering from the effects of hard water. Here at Mark Vernon, we have produced this guide to Worcestor Bosch Boilers and hard water.

What is hard water?

Hard water is simply water that also contains dissolved magnesium and calcium ions. These dissolve into the water from different rock types, which is why different parts of the country have different levels of hard and soft water. In the North West, the water is often moderately hard. But what does this means for your boiler?

Boilers and hard water

Because of the additional ions, hard water can be damaging to not only your boiler, but your central heating system as a whole. This is because, when the water is heated, the ions are left behind, bonding to become calcium carbonate. More commonly known as limescale. This limescale can be damaging to your boiler, your pipes, and your radiators.


Inside your boiler, limescale can cling to the heating element, and prevent your boiler from heating the water efficiently. As a result, your boiler will need to use more fuel, and more energy, to heat your home. This will cause a rise in your bills, and can out additional strain on your boiler.


Hard water also effects your pipes. Pipes that have a calcium carbonate build up cannot conduct the heat properly, and also have restricted access for the gas and water to flow through. As a result, your home will not be heated as quickly as it used to be, and again, your boiler will need to work harder to power your home.


Finally, hard water also builds up in your radiators. This means that cold spots will develop inside your radiator, and your home will not feel as warm as usual.

If you notice any cold spots, or hear any whistling or rattling noises from your boiler or pipes, contact a professional team, like us here at Mark Vernon.