Do you need a whole house water filter?

A whole house filter treats water where it enters your home, so every tap and shower gets the benefit. That sounds like the obvious choice, but it is not right for everyone. Here is how to decide.

What it does

A whole house system sits on the incoming mains, usually close to the stopcock. Most use one or two large cartridges:

• A sediment filter catches sand, rust and other particles.
• A carbon filter reduces chlorine and improves taste and smell.

Because the cartridges are large, they can handle the flow of a whole house and tend to last longer than a small under-sink filter.

What it does not do

A whole house filter is not a softener. It will not stop limescale, because calcium and magnesium pass through. If you want to deal with hard water you need a softener or a scale reducer, and some homes fit both.

It is also not the same as reverse osmosis. If your concern is what is in your drinking water, an RO system at the kitchen tap goes much further.

Mains water or a private supply?

This makes the biggest difference to what you need.

On mains water, your supply is already treated to be safe. A whole house filter is mainly about comfort: less chlorine in showers and baths, better tasting water from every tap, and less grit in appliances.

On a private supply, such as a borehole, well or spring, things are different. The water may contain bacteria as well as sediment, and you are responsible for keeping it safe. This is where UV sterilisation comes in.

Where UV fits

A UV steriliser passes water through a chamber lit by a UV lamp, which stops bacteria and other micro-organisms from multiplying. It adds no chemicals, but it has two limits:

• It only works on clear water, so a sediment filter is fitted before it.
• It does not remove anything. Chemicals and minerals go straight through.

Lamps lose strength over time, so they need replacing on schedule even while they are still lit, usually once a year. If you are on a private supply, have the water tested first so you know what you are treating.

Is it worth it for you?

A whole house filter makes sense if:

• You notice chlorine throughout the house and not just at the sink.
• Sediment is getting into your taps and appliances.
• You are on a private supply. In that case it is often essential.

If you only care about drinking water, an under-sink system will cost less and may do more.

Before you buy

Check the size of your incoming pipe and your flow rate, as a system that is too small will reduce the pressure at your taps. You will also need space near the stopcock and room to change cartridges.

Browse our whole house range, or call us on 0121 557 5532 and we will help you size it properly.