Water Softener Buying Guide: How to Choose a Water Softener

If you’re reading this water softener buying guide and are looking to find out how to choose a water softener – you’ll already know two things:

1. You have hard water and are facing hard water problems such as limescale in the home.

2. You need a water softener.

This guide specifically aims to tell you everything you need to know before purchasing a water softener and guide you to choose the right system for your home.

This guide will answer key questions including:

1. What is a Water Softener & How Does a Water Softener Work?
2. Water Softener Regeneration – What is it?
3. The Different Types – Which Water Softener Do I Need?
4. What is The Difference Between Electric and Non-Electric Water Softeners?
5. What is the Difference Between a HF and HE system?
6. Should I Buy a Salt or Salt Free System?
7. How is a Water Softener Maintained and What Are The Running Costs?
8. Should I Buy a Block or Tablet Salt Softener?
9. How Much Does a Water Softener Cost?
10. What are the different water softener brands and which is the best?
11. How is a Water Softener Installed?
12. Are Water Softener Certifications and Warranties Important?
13. Can I Drink Softener Water?

You can click specific questions above to jump straight to that section.

Before you start: some questions…

Before you dive into this detailed guide, there are some baseline questions you need to know the answers to:

• How many bathrooms does your home have and how many people live in your home?

One of the biggest factors which will determine the type of water softener you need, is how many bathrooms your home has and how many people contribute to the water usage. Homes with more bathrooms or more people using the water at any one time, may require a larger flow rate.

• What type of plumbing system does your home have?

You need to know what type of plumbing system your home has. For example, some homes are gravity fed systems (with a water storage tank), and other systems are high flow with combi boilers. 

Homes with storage tanks and a gravity fed system have a constant supply of pressure. Whereas, high flow systems, generally have larger pipes and the flow of water has a higher pressure.

The water softener you select needs to be suited and designed to your home system. There will be more detail on this within the guide, for now you just need to make a note of what system you have.

• How hard is your water on the ppm scale?

You can find out a rough estimate of the hardness of your water from a hard water map. Or you can order water testing strips if you want to know the exact ppm reading. Water hardness affects (and decrease) the flow rate of a water softener.

• Where is your stop tap located? How much space do you have?

Where the stop tap is located is important because this is where the softener is installed. This is usually under neath the kitchen sink. For that reason, it is important to know where your stop tap is and how much space you have available. This will help you choose a system which can fit in your home.

• What size pipes does your home have? 

Your pipe size is important for the installation and choosing an installation kit. New homes generally have 22mm pipes, older homes 15mm and some large homes can have 28mm pipes.

1.    What is a water softener? How does a water softener work?

A water softener is a device and home appliance that is connected to the home plumbing system in order to remove hard water and prevent limescale build up. 

When fitted, the softener is usually installed near the main stop tap, where it intersects the mains supply of water entering the home. This is generally underneath a kitchen sink, in the utility room or in the garage.  

As hard water enters your home, it passes through the water softener, which removes hard water minerals such as calcium and magnesium. This effectively filters and treats the water, allowing soft water to flow freely throughout the entire home. 

A domestic water softener works using a process called ‘ion exchange’. Inside a water softener, there is an “internal resin”, made up of tiny beads that have sodium ions attached to them. Without getting too much into the science and chemistry…

The softening process involves:

• 1. As the water, containing hard calcium and magnesium, passes through the softener. As it flows, these ions are attracted to the resin where they exchange, or swap out, with soft sodium ions.
• 2. The calcium and magnesium ions are then effectively “stuck” to the internal resin and filtered out of the home’s supply of water.

• 3. The soft water produced, then leaves the system and enters the home. This softer water contains small amounts of sodium, but no limescale – it can actually help to remove existing limescale.

• 4. As time goes on and water is used, the internal resin begins to become saturated and filled with hard limescale minerals. And so, the system has to clean itself through an automatic regeneration process. To do this, salt water is passed through the tank and the waste calcium and magnesium is flushed down a drain pipe and into the waste drain.

2.    What Is Water Softener Regeneration?

Regeneration is how a water softener cleans its internal resin. 

When a water softener becomes filled with calcium and magnesium, it needs to regenerate and clean itself. Water softeners use salt to do this. They contain a brine tank with a brine solution. The brine solution flushes through the system, replacing used up sodium ions. The hard minerals displace and are flushed out and into the drain.

3.    What are the different types of water softener and which one do I need?

The type of water softener you need depends on: 

• how many bathrooms you have, 
• how much water you use/how many people are in the home 
• and the type of plumbing system you have. 

The different types of water softener:

Single Tank Design

A single tank water softener is the simplest design and function best in smaller homes. These systems have one singular tank, which contains the internal resin that treats hard water. The main things to know about these products are:

1. The soft water flow is not constant when the system is regenerating and cleaning itself. This is because there is just one tank, so the soft water supply is cut off during this time.
2. Many available single tank systems are electric and require electricity. This can make them difficult to set up and install.
3. Most single tank products require tablet salt vs block salt.
4. Single tank softeners are generally larger than twin tank systems, and they can waste a lot of water and use a lot of salt. 
5. They have an average flow rate, for smaller homes with 1-2 bathrooms.
6. You may not be able to drink the water and the drinking water feed needs to be isolated.

Twin Tank Design

A dual tank water softener has two independent cylinder tanks which both contain internal resin. When the first tank reaches its maximum capacity and is saturated, the system switches to the second tank – so the first can regenerate and clean itself.

This means the softener can continue delivering soft water without interruption, and the supply to the home is constant. The main features of a twin tank softener are:

1. Twin tank designs have a higher flow rate and so suited for homes with 2-3 bathrooms.
2. Two tanks give a better performance. They deliver soft water 24 hours a day.
3. They tend to be more efficient. Usually using less water and salt per regeneration than a single tank.
4. They are generally smaller and more compact in size, but more complex in terms of internal parts.
5. Most systems are non-electric and so automatic.
6. They can use block or tablet salt.
7. You can get standard or large twin tank softeners. Large homes require a greater flow rate.
8. The soft water produced is usually drinkable, depending on your water hardness and within general sodium requirements.

Which Type Do You Need?

Which design you need depends on the size of your home and water use:

For homes with 1-2 bathrooms – single tank softeners are suitable (flow rates 20-40L/min). Homes with 2-3 bathrooms a standard twin tank machine is required (flow rates of 40-60L/min). For large homes a larger water softener with higher flow rate is needed (flow rates of 60-80L/min).

4.    What is the difference between electric and non-electric water softeners?

Electric Water Softeners: Time controlled 

An electric water softener needs a constant supply of electricity in order to work and regenerate. For that reason, you will need a plug socket available under the sink when planning for the installation. 

Electric softeners function using time-control, meaning they regenerate at specific time intervals and use an electric timer to time the process. 

You will have to manually set and program the system to ensure the regeneration occurs at a time when it is least likely to interfere with your daily water usage. 

If you are looking to purchase an electric system you should be aware of the following:

• They need a supply of electricity and a plug socket. Which can make the installation more difficult.
• They are usually single tank systems.
• The regeneration is manually timed.
• They are less efficient. When set to a specific time interval a regeneration can occur before the internal resin is actually saturated. As a result, this might waste both water and salt.
• Electric systems require a regular service every 2 years to ensure they are safe for use. This can be expensive in terms of call out fees. 
• They have higher running fees and can influence energy bills.
• You may experience power trips in the home.

Non-electric Water Softeners: Volume controlled

Non-electric water softeners work without electricity and use the kinetic energy generated by moving water. The are fully automatic, with no need for timers or controls and relying on water usage measurements.

They are therefore, volume controlled or metered water softeners. To put things simply, they measure the amount of water flowing through the softener and regenerate automatically when the resin inside is saturated. Not only that, but they can be set at precise water hardness levels.

By setting the softener to a specific water hardness level, this allows for more accurate regeneration calculations.

When considering a non-electric softener you should know the following:

• They are more efficient. They regenerate only when they need to and use less water and salt.
• They are easy to install and use. There is no need for timers or controls and they don’t require a plug socket.
• They have lower running costs.
• They are generally twin tank designs but you can also find non-electric single tank systems.

5.    What is the difference between a HE and HF water softener?

Water softeners can come in HE or HF versions. 

HE stands for High Efficiency. A HE water softener works with low pressure systems, homes with gravity fed systems and water storage tanks. A HE design normally has a lower flow rate, saving more salt and water when it is used in a low pressure system.

HF stands for high flow, this is the type of softener you will require if you have a combi boiler and standard high flow system. HF water softeners have higher flow rates and so can compensate for larger pipes and higher water pressure. 

6.    Salt Vs Salt Free Systems

Most home owners who are searching for salt free softeners are concerned about sodium intake. However, with a salt-based softener, drinking water taps and feeds can be isolated. An isolated drinking water feed provides a regular hard water drinking supply. 

In terms of water softening – a salt based softener is the most effective and most reliable method, with salt-free systems giving limited results. 

7.    How can I maintain a water softener and what are the running costs?

A water softener is maintained using block or tablet salt, which is required to make the brine solution used in the regeneration process. 

Running costs of a water softener depend on: 

1. If the system is electric or non-electric.
2. How efficient the machine is. As part of the general specification, you can identify efficiency by looking at how much salt and water a system uses per regeneration.
3. Water usage. Bigger families who use more water will saturate the resin quicker, and so more regenerations may occur. 
4. The salt usage. A water softener needs to have a constant supply of salt. You can expect an average family home to use around 4kg of salt per person, per month. But this can vary depending on water usage and efficiency of the product itself. 
5. The hardness of you water. 

Other costs to maintain a water softener include fees for servicing every 2-3 years. Services keep your softener in tip top shape, helping to clean the internal resin and remove any issues such as a blocked brine valve.

8.    Should I buy a block salt or tablet salt water softener?

The type of salt you need depends on the type of water softener you choose. Block salt water softeners tend to need less salt in general and be more efficient. 

The main difference however is within the storage and usage of the salt. Tablet salt comes in bags which 10- 25kg. These bags can be difficult to store in homes with limited space and they are prone to spillages and wastage. Blocks of salt can be more expensive than tablet salt to buy, but are smaller and easier to store and refill. They come in 8kg bags with two blocks inside. 

There is no difference between the actual brine solution that is made from block salt or tablet salt. 

9.    How much does a water softener cost?

Water softener prices can vary depending on the brand, model and design you choose.

Single Vs Twin Tank

The cost of a single tank water softeners ranges from £500 – £800. Standard Twin tank softeners can cost anything from £850 – £1600, depending on quality, brand and warranty.

Single tank designs are typically simpler, suited for smaller homes and have lower flow rates. Therefore they are lower in price. However, the running costs can add up to be more than a twin tank systems – thus making the overall costs more expensive over the years.

The Size & Flow Rate

Large water softener: £1700 – £2000.

A Large water softener is made for larger homes with 5+ bathrooms. They are more expensive to buy than standard twin tank systems, which are intended for homes with 2-3 bathrooms. The size of these products are bigger and their flow rates are also a lot larger, ranging anything from 60-80L/min.

10.    What are the different water softener brands and which is the best? What are the best water softener companies?

There are many different brands of water softener available to buy online and offline. 

In the UK, some brands sell through exclusive distributors – making their products more difficult to find. Some common brands of water softener include: Kinetico, BWT, Monarch, Water2Buy and Harvey.

Harvey Vs Kinetico 

The best brands you can buy are Kinetico and Harvey. 

Kinetico are a popular and renowned brand in the USA, Europe and the UK. This brand is one of the best you can bu quality available. They have been around the longest and actually created the non-electric water softener. Kinetico products are the most expensive – but for good reason.

In the UK, Harvey is the most popular water softening brand – especially in London and Southern UK areas. You can only find products from Harvey through exclusive retailers across the UK, they also offer their own install and supply service. Both Harvey and Kinetico only sell non electric water softeners – due to these designs being the most economic, reliable and efficient.

The best company to purchase the softener from can depend on several factors. Warranty, product quality and price are important features to look out for and compare.

11.    How to install a water softener?

A water softener install involves fitting the system where the stop tap is located. This is usually underneath the kitchen sink or in a utility room, depending on the size of the system and space available in your home. When installing a large water softener, it may be advisable to do so in a garage or plant room. 

Some people can find their stop tap in unusual locations. In these cases, the softener may need to be fitted near the outdoor stop tap and outside. In this circumstance, the softener requires an external cabinet to control temperature and protect it from weathering.

During an installation, you will require a bypass valve and it is common to rearrange and move pipes. For that reason, you will usually require a plumber to carry out the installation.

12.    Water Softener Certifications and Warranty

It is important when learning how to choose a water softener, to make sure the product has certification. WRAS is the UK standard certification and the most important to look out for. 

Warranties can vary depending on the make and model of the product. They can range from 2 -10 years.

13.    Can I drink softened water?

In most cases, softened water is safe to drink and within the daily recommendation requirements.

Do not consume soft water regularly if:

•  You follow a medically prescribed low sodium diet 
• Are bottle feeding a small infant. 

In these cases, you will need to isolate the hard water feed or have a reverse osmosis water filter installed. This may also apply when softening very hard water, or purchasing a low-cost budget system (usually single tank). This is because the level of sodium may exceed UK recommendations and intake. Therefore, it is not recommended to drink the water.

Some people actually prefer the taste of hard water, opting for an isolated hard water drinking supply. In most twin tank systems – soft water is safe to drink.

Your Next Steps

We hope this water softener buying guide was helpful. Now you know everything you need to know about how to choose a water softener, you can start your search online. Why not read some of our water softener reviews to find out more.