Questions to ask before purchasing a whole house water filter system

A whole house water filtration system is an excellent choice for anyone wanting to remove impurities like chlorine from their drinking and bathing water. With benefits including cleaner tasting water on tap and softer skin and hair, it’s no surprise that these are among our most popular products.

With so many varieties available it can sometimes be a job to choose which system is right for your home. People often phone us saying they want filtered water throughout their whole house, but have no idea which system to go for as there are so many varieties.

We’ve written this simple guide to help you decide which whole house water filter is the right choice for you...


 1. How many people live in your house?

It’s really important to take the size of your household into account when choosing a whole house water filtration system. The higher the number of occupants, the more water will be used. This means that you need to select a unit with a sufficient filter capacity in litres. We’ve done the maths for you, so you can sort our whole house filters online by number of household occupants, or view the simple guide below:

Suitable for 1-4 occupants

Suitable for 5+ occupants

2. Do you have a low pressure or combi boiler?

Some of our units are not suitable for households with low water pressure or combi boilers. If this applies to you, then only the below units will be suitable. If you do not have low water pressure or a combi boiler, you can use any of our whole house units.

Units suitable for low pressure/combi boiler

3. How much space do you have available?

You’ll need to position your whole house water filter as close to your stopcock as possible, to ensure that all water is filtered before it reaches various taps in the house. Depending on the location of your stopcock, you could put your whole house water filter in a kitchen cupboard, an airing cupboard or hallway cupboard. The dimensions for each of our units are clearly displayed on our website to help you. We advise leaving an extra 10cm of space below your unit so that you can easily replace the filters when the time comes.  

Best units for small spaces

4. What do you want to remove from your water?

A useful next step is to think about what impurities bother you in your water.

Chlorine is the chemical that most people want to take away. This can not only give water an unpleasant taste and smell, its abrasive nature can also be drying on skin and hair. Many people find that after de-chlorinating their household water, their eczema symptoms improve and their skin feels softer. Drinking water tastes far crisper and cleaner without chlorine, too.

All of our whole house water filters contain at least one carbon block filter. This filter removes up to 99.99% of chlorine.

Organic compounds are also a common concern. Trihalomethane, herbicides, phenols and pesticides fall under this category. Again, the carbon block filter found in all of our whole house units will remove virtually all of these.

Heavy metals include lead, mercury, arsenic, cadmium and silver. Many people are concerned about the potentially toxic effects that even small amounts of these heavy metals can have on the body. To remove these, you’ll need a special heavy metal filter system, like the WH3HM or the WH6HM. To give you an idea of how efficient these heavy metal filters are, the levels in brackets below are in unfiltered water and levels once the water has been filtered (particles per million):

Arsenic (5)  0.01

Lead (2.05)  0.1

Mercury (1)  0.001

Cadmium (5)  0.01

Silver (1)  0.01

 

Filters which remove heavy metals

5. Are you prepared to replace the filters?

Just like an air purifier, a whole house water filter needs care and maintenance to ensure the filtered water stays an optimal quality. We recommend that a pre-filter (if you have one on your unit) is replaced every 6 months. Depending on the number of household occupants and how much water is used, we advise replacing your carbon blocks every 6-12 months. We’ll remind you when your replacement filter is due by automatically adding you to our filter reminder list. This means you can sit back and relax!

Once you have removed the old filters, we recommend running chlorinated water through your whole house filter system for 5-10 minutes before installing the replacement filter.

6. Can you install it yourself?

Our whole house units can be installed yourself at home, provided you have decent DIY skills. They come with clear and detailed installation instructions. If you’re not confident in installing it yourself, a local plumber should be able to do this for you without problems.

7. Should you purchase an additional drinking water filter?

Drinking water that has only passed through the whole house unit should still be cleaner than the water that normally comes out of your tap. Our whole house systems remove the most common contaminants, as well as organic compounds like oestrogen. However, for the ultimate in taste, quality and purity, we recommend investing in an undersink drinking water filter to complement this. The ceramic structure of the Ultracarb filter contains silver, offering enhanced protection against bacteria, trace organics and cysts. 

8. Any other considerations?

After installing a whole house unit, you might experience a drop in water pressure of between 5 and 10% depending on which system you opt for. Flexible fitting kits are available for those with a megaflow system or an already low water pressure. You’ll need to fit a pressure regulator if your flow rate is over 80psi to bring it down to 70psi.  


We hope that this guide has been clear and useful. If you need any further assistance, please call our friendly and knowledgeable customer advisors on 0845 450 5950 or 01453 752216. We’ll be pleased to talk you through the options and provide after-sales support.

View all of our whole house water filtration systems here.