Water hardness

Understanding Water Hardness and Its Impact on Plumbing

Water hardness refers to the amount of dissolved minerals, particularly calcium and magnesium, present in the water. These minerals can create issues with plumbing systems, such as blockages and reduced efficiency of chemicals like detergents. Ideally, water should be moderately hard and have a stable pH to minimise these problems.

In cases where the local water supply is naturally soft, special precautions should be taken to protect plumbing. Soft water, if untreated, can be more corrosive to pipes and fixtures. However, this risk does not apply to water softened using a properly maintained water softener system. By ensuring the plumbing system is well designed and installed, its lifespan can be increased, and the chance of leaks is reduced.

Water Hardness Levels

Water hardness is commonly measured in parts per million (ppm), with one ppm representing one milligram of calcium per litre of water. In the UK, water hardness can vary from 0 to over 300 ppm. Generally, water tends to be harder on the eastern side of the Pennines compared to the west. Besides the level of hardness, pH balance is equally important, as excessively acidic or alkaline water can damage plumbing and reduce the efficiency of chemicals used in household appliances. For example, when installing a dishwasher, it’s essential to test the water hardness and adjust the settings as recommended by the manufacturer.

Common Plumbing Problems Due to Hard Water

A frequent issue in homes with hard water is the buildup of mineral deposits in the secondary heat exchangers of combination boilers. This can lead to poor flow from hot taps. If you notice reduced hot water flow throughout your home, it may be necessary to replace the heat exchanger. When upgrading or replacing taps for functional reasons (not just aesthetics), it’s helpful to inform your plumber, as the underlying cause might need addressing.

Origins of Hard Water

Hard water typically results from natural processes. As water travels through areas rich in limestone, dolomite, or gypsum, it picks up minerals that increase hardness. Industrial activities can also contribute to this.

Preventive Measures

To ensure your water supply has moderate hardness and a stable pH, regular testing is advisable. This can help prevent problems and keep your plumbing system running smoothly.

Frequently Asked Questions:

1. What is water hardness? Water hardness refers to the concentration of divalent metal cations, primarily calcium and magnesium, in the water. Hard water typically has higher levels of these minerals.

2. Why does water hardness matter for plumbing? Hard water can cause scale build-up in pipes, fixtures, and water-based appliances, reducing their efficiency and potentially leading to damage or blockages. On the other hand, naturally soft water can be corrosive, which can wear out pipes and fixtures more quickly.

3. How is water hardness measured? Water hardness is measured in parts per million (ppm), with one ppm equivalent to one milligram of calcium per litre of water. In the UK, water hardness levels can range from 0 to over 300 ppm, depending on the region.

4. What problems can hard water cause in a central heating system? Hard water can lead to scale build-up, which may block components like the secondary heat exchanger in combination boilers. This blockage can reduce hot water flow and cause inefficiencies in heating.

5. How can I test the hardness of my water? Water hardness testing kits are available and can provide a simple way to measure the mineral content in your water supply. Some appliances, such as dishwashers, may come with a kit or instructions on how to adjust settings for optimal performance based on water hardness.

6. Can water softeners help with hard water issues? Yes, properly designed water softeners can treat hard water by removing calcium and magnesium ions. This helps prevent scale build-up and prolongs the life of your plumbing system and appliances. It's essential to note that softened water is different from naturally soft water, and softened water does not have the same corrosive properties.

7. Why is pH important in relation to water hardness? The pH level indicates how acidic or alkaline the water is. Water that is too acidic or too alkaline can damage plumbing fixtures and decrease the effectiveness of cleaning chemicals. Maintaining a stable pH, alongside moderate hardness, is key to preserving plumbing health.

8. Is there a geographical difference in water hardness across the UK? Yes, water hardness varies across the UK, generally being higher in areas east of the Pennines and softer in regions to the west. This variation is due to differences in the underlying geology, such as the presence of limestone or dolomite.

9. What causes hard water? Hard water forms as it percolates through geological formations like limestone, dolomite, or gypsum. These rocks dissolve into the water, adding calcium and magnesium. Additionally, industrial activities can also contribute to local water hardness.

10. How can I manage hard water problems in my home? You can consider installing a water softener or descaler to minimise scale formation. Additionally, regular maintenance of appliances and your plumbing system, such as power flushing central heating systems when needed, can mitigate the effects of hard water.