What is hard and soft water, should you care and does hard water kill boilers?
Hard and soft water is a way of categorising the level of minerals found in water that flows from domestic water outlets.
Broadly speaking, hard water has more dissolved minerals and soft water has less.
But why do some areas of the UK have hard water and others soft?
And how can the type of water you have affect your heating system?
Let’s take a look!
What is Hard and Soft Water?
Throughout the UK there is a mixture of hard and soft water areas.
However, it’s important to note that while hard water can cause various issues (e.g., the build-up of limescale in your pipework), both hard and soft tap water are safe to consume.
As touched on, hard water contains more minerals than soft water.
These minerals are often the result of dissolved rocks, however, these minerals may also comprise a range of other materials (e.g. excess calcium or excess magnesium).
While soft water is not totally free of minerals, it contains a sufficiently low level to the point that it should not cause the same problems as hard water.
To explain the process of what makes water hardened in more detail, we need to start with where the minerals that end up in hard water begin their journey.
Of course, all water comes from nature and it should be noted that rainwater, some of which eventually makes its way to our homes for domestic use, is naturally soft.
With that being said, rainwater is a little acidic due to the CO2 present in the atmosphere.
This type of acidity is different from the problem of ‘acid rain’ which once raised concerns with experts and ordinary people alike.
Acid rain was the result of other gasses and created a greater level of acidity than CO2 can create in the clouds.
As rainwater lands, it’s soaked into the ground before making its way through the soil and rocks below.
Due to the carbonic acid featured in the rainwater, it can dissolve certain minerals along the way, resulting in harder water, which can eventually end up in the pipework leading to properties.
A scientific measure of hard vs soft water is based on the number of minerals (as measured in milligrams) per litre of water.
In hard water areas, there will be over 200 mg/l of minerals, whereas, in soft water areas, the quantities are under 100 mg/l.
Areas with water featuring 100 to 200 mg/l of minerals are known as ‘medium hard water areas’.
Why Do Some Areas Feature Hard Water and Others Soft Water?
The main reason why some regions will feature hard water or soft water is largely dependent on whether or not the water used for properties has had time to collect underground.
After all, water making it underground is the key reason why rainwater hardens in the first place.
To provide an example, in many parts of England, water is initially pumped out from underground aquifers, which are rocks that store water in spaces and cracks where possible. This is called groundwater.
How exactly this will affect the water that is sent to homes will vary. However, in general, when groundwater is used, it will likely be hard water.
To give some more specific examples, the rocks featured in underground aquifers in the southeast of England consist of chalk while the predominant underground rocks that store water in Yorkshire is limestone.
Therefore, hard water in the southeast of England will consist more so of chalk with limestone being more present in Yorkshire domestic water.
Soft water tends to be found in regions of Scotland, the north of England, Wales and Northern Ireland.
Domestic water that is harvested in Scotland and Wales tends to be extracted from lakes, rivers and reservoirs (a.k.a., surface water).
Naturally, surface water will be soft water as it hasn’t had the chance to accumulate minerals.
Beyond that, it is possible in some cases for groundwater to remain soft or at least medium hard.
This is because, in some regions, the rocks found in underground aquifers will not be as soluble as many other minerals.
In Nottingham, for instance, since the dominant underground rock that comes into contact with groundwater here is sandstone (a less soluble rock), the water remains relatively soft.
How Does Hard Water Affect Boilers?
There are many ways in which hard water can impact properties.
Aside from the effects it can have on boilers/heating systems (which we’ll discuss in depth shortly), hard water can cause a range of problems including opaque glassware and spotted dishes from use in the dishwasher, unusual stains in the toilet and poor showering water pressure.
Moving on to boilers and heating systems, there are various ways in which hard water can cause issues (thankfully, there are steps you can take to remedy these problems, which we’ll explore in the next section).
The Build-up of Limescale
As we mentioned, hard and soft water are both safe to drink in the UK, but among the issues listed above, hard water can cause a few significant problems for boilers/heating systems.
For starters, the minerals featured in hard water can result in large chunks forming as limescale deposits.
As limescale accumulates, it can cause blockages in pipes, radiators, taps and elsewhere in your system, including the boiler itself.
As limescale deposits accumulate the amount of free space in the pipe will be reduced, limiting the ability for water to flow as it should.
This can in turn cause cold spots in radiators or at least make it harder for them to warm up sufficiently.
Furthermore, the build-up of limescale can act as an insulator inside your heating system’s pipework.
As a result, this will make the inside of your radiators warmer, encouraging further limescale build-up, thus setting off a growing feedback loop.
By the time the issue of limescale is causing an array of noticeable issues, you’ll likely have to splash out on having your heating system power flushed which will likely set you back somewhere in the region of £400 to £500.
Other potential expenses caused by this problem include:
Metal components that need repairing due to overheating which is initially the result of limescale build-up
Higher heating bills as a result of your boiler needing to work harder to pump water through your heating system
General Corrosion
Along with the issue of limescale deposits, hard water can gradually corrode the pipework of your boiler and heating system, which can eventually necessitate that the pipework is replaced.
Calcium deposits can play a significant role in causing cumulative damage to your heating system’s pipework.
Whether it be down to limescale deposits, corrosion, or both, hard water can lead to issues which can prove costly in the long run.
Therefore, if your property has a hard water issue, you’ll want to take steps to soften it, thus saving you money over time.
How to Turn Hard Water Soft and Prevent Costly Boiler Issues
So, how do you turn hard water soft?
There are three primary solutions, specifically the use of a water softener, chemical softeners or an ion exchange filter.
Water Softener
This device can be used to rid hard water of calcium and magnesium ions.
A water softener is most likely to be added to a kitchen sink or another location that is easily accessible.
As the mains supply water arrives in your heating system, the water softener uses resin beads to create a process called ion exchange.
This results in certain minerals being removed. Salt is also added in place of the minerals.
After this point, the undesired minerals will be completely removed from your heating system, leaving you with totally soft water for your heating system.
It’s important to note that if a water softener stops functioning, hard water will make its way back in.
Moreover, the salts used in this device will need replacing from time to time.
Limescale reducer
Alternatively, you could install a limescale reducer to simply prevent limescale from accumulating in your heating system.
Limescale reducers change the chemical properties of water inside a boiler, thus preventing the build-up of limescale deposits.
There are various types of limescale reducers, including:
Magnetic descaling - Uses a magnetic field to limit the formation of deposits.
Electronic scale reducer - Features electrical impulses designed to prevent limescale crystals from developing.
Chemical scale reducer - The chemical treatment used in such products is designed to bind with minerals, making it less likely that limescale will accumulate.
Reverse osmosis - In short, this is a process whereby a semipermeable membrane is used to filter out minerals and impurities in water, reducing the chance of limescale build-up.
Other considerations
While a limescale reducer or water softener could prove helpful for protecting your boiler/heating system from limescale and eventual overheating issues, there are other steps that can specifically address hard water issues in other areas.
Here are other methods of addressing hard water issues in your property and for what purpose:
Certain chemical softeners can be added to a washing machine to limit how hard water affects your clothing. Just be sure to get the right product for your machine.
An ion exchange filter is a great way of making your tap water soft. Similar technology exists to improve the quality of the water exiting your shower head.
Cost of Addressing Hard Water Issues
Note: You cannot power flush a heating system. As with many boiler/heating system jobs, it is only suitable for a qualified professional.
So, how much might it cost to deal with hard water issues?
Well, this will depend on whether you are simply looking to get ahead of potential problems, deal with boiler problems that have already arisen, or both.
Of course, if hard water has already led to issues such as limescale accumulation, it would certainly make sense to address this and then take measures to prevent it in the future.
Here is the cost of addressing hard water issues DIY:
Adding a water softener - £250 to £1,500
Chemical limescale reducer - £10 to £50
Fitting a magnetic or electronic descaler - £50 to £300
If hiring a professional, the costs will include an additional labour fee of £30 to £60 per hour.
Considering most jobs will take around 1-2 hours, it will not likely add an enormous amount to your bills.
However, if you need to have other problems addressed which require the work of a professional, your total bill is likely to end up as follows:
Power flush - £400 to £500
Repairing a boiler component - £50 to £200
Replacing a boiler component - £200 to £800
Having a new boiler installed - £800 to £2,800
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