Mains Water Filters

A mains water filter, also known as a whole house water filter, is installed on the rising main where water enters your property. Instead of filtering water at a single tap, it treats the incoming mains supply before it is distributed around your home, helping to improve water quality at every cold water outlet.

Whether you're looking to reduce sediment, rust particles, chlorine or other unwanted impurities, our range of mains water filters includes solutions for everything from apartments and family homes to larger properties and commercial premises. With a choice of sediment filters, carbon filtration systems and specialist whole house filters, you can select a system that matches your water quality concerns and the flow rate your property requires.

If your main priority is producing filtered drinking water from your kitchen tap, rather than filtering the water entering your home, take a look at our Water Purifiers, which are designed specifically for point-of-use drinking water filtration.

As UK water filtration experts, if you are unsure which of our home water filters is going to be right for you, then please call us on 01352 838 281 or send us a message via our helpdesk.
 

Your Guide to Choosing the right Mains Water Filter

Choosing a whole house water filter isn't simply about selecting the largest housing or the finest filter cartridge. The right system needs to be matched to your property's plumbing, water usage and the improvements you want to make to your mains water.

Unlike drinking water filters, which are designed to supply filtered water at a single tap, mains water filters operate at your property's normal mains pressure and flow rate. That means the system needs to be capable of supplying enough filtered water for your household without unnecessarily restricting flow.

The best choice depends on several factors, including the size of your property, the number of bathrooms, the expected water demand and the type of filtration required. Some homeowners simply want to reduce sediment and rust particles, while others are looking to improve taste and odour throughout the home or install specialist filtration to address particular water quality concerns.

If your property is supplied by mains water, this guide will help you understand how whole house water filters work, how to choose the right size system and the key factors to consider before buying.

If you have a private water supply, such as a borehole, spring or well, your filtration requirements are likely to be different. We recommend visiting our Private Water Supplies category or contacting us for advice on the most suitable treatment system.

Please call us on 01352 838 281 or send a message.

Why install a Mains Water Filter?

A mains water filter is fitted where the incoming cold water supply enters your property, allowing water to be filtered before it reaches your plumbing system. This provides a central filtration point rather than relying on individual filters at separate taps.

Improve Water Quality throughout your Property

Filtering water at the point of entry means every cold water outlet can benefit from improved water quality, whether it's your kitchen, utility room, bathroom or outside tap.

Reduce Sediment and Rust Particles

Small particles such as rust, sand and suspended solids can occasionally be present in mains water, particularly following  maintenance work on the local water network. A whole house filter helps capture these particles before they circulate through your home's plumbing.

Help Protect Plumbing and Appliances

Cleaner incoming water can help reduce the amount of particulate matter reaching taps, valves, and household appliances. Washing machines, dishwashers and other water using appliances all benefit from receiving cleaner water.

Improve Taste and Odour

Where activated carbon filtration is used, many mains water filters can reduce chlorine, helping to improve the taste and odour of water throughout the property.

Tailor the Filtration to your Water

Not every home has the same water quality concerns. One of the advantages of a mains water filter is that you can choose a filtration system designed for your particular requirements, whether that's sediment reduction, taste and odour improvement, heavy metals or specialist applications.

Choosing the Right System for your Plumbing

The type of plumbing in your home can also influence the most suitable solution.

If your property has an open vented system with a header tank and hot water cylinder, filtering cold water supplies that you use most often may provide the greatest benefit.

If you have a closed, pressurised system, such as a combi boiler or unvented hot water cylinder, a whole house filter installed on the incoming mains supply is often an effective way of treating water before it is distributed throughout the property.

If you're unsure which approach is right for your home, our team is always happy to help you choose the most appropriate system.

What can a Mains Water Filter Reduce?

A mains water filter is designed to improve the quality of the water entering your property before it reaches your taps, showers and appliances. The contaminants a system can reduce will depend on the type of filter cartridge installed, so it's important to choose a system that's matched to your water quality and your requirements.

Sediment

Sediment is a common reason for installing a whole house water filter.

Although UK mains water is carefully treated, small particles such as sand, silt and rust can occasionally enter the water supply, particularly after repairs or maintenance work on the local water network.

A sediment filter helps capture these particles before they circulate through your home's plumbing, helping to improve water clarity and protect downstream appliances and valves from unnecessary debris.

Rust Particles

In some properties, particularly those with older pipework, tiny rust particles may be present in the incoming water supply.

A suitable mains water filter can help reduce these particles before they reach taps, showers and appliances, contributing to cleaner water throughout the property.

Chlorine

Chlorine is added to public water supplies to keep drinking water safe during distribution. While essential for disinfection, some homeowners prefer to reduce chlorine because of its taste and odour.

Where activated carbon filtration is used, many mains water filters can reduce chlorine throughout the home's cold water supply, making water more pleasant for drinking, cooking and general household use.

Taste and Odour

Activated carbon filters can also reduce many of the compounds responsible for unpleasant tastes and odours in mains water.

While taste is often associated with drinking water, improving water quality throughout the property can also make water more pleasant for preparing food, filling the kettle and other everyday household tasks.

Choosing the Right Whole House Water Filter

Not every property requires the same filtration system. Choosing the right mains water filter involves understanding both your water quality and your household's water demand.

Flow Rate Matters

One of the most important considerations is flow rate.

Unlike an undersink drinking water filter, a whole house system may need to supply several outlets at the same time. For example, someone may be having a shower while another tap is running or a washing machine is filling.

Selecting a system that's appropriately sized helps maintain good water flow throughout the property while allowing the filter cartridge to perform effectively.

Cartridge Size

Larger filter housings generally contain larger cartridges with a greater filtration capacity. This can be particularly beneficial for larger households or properties with higher water consumption.

Smaller properties with lower demand may not require the largest system available, so choosing the right size can help balance performance, maintenance and running costs.

Matching the Filter to the Water

Different filter cartridges are designed for different purposes.

Some are intended primarily for sediment reduction, while others use activated carbon to reduce chlorine, improve taste and minimise odours. Specialist cartridges are also available for particular water quality concerns.

Selecting the right cartridge is just as important as choosing the correct filter housing.

Looking after your Mains Water Filter

Like any filtration system, a mains water filter requires routine maintenance to continue performing effectively.

Replacement cartridges should be changed at the intervals recommended for your chosen filter, or sooner if water quality, flow rate or pressure indicate that the cartridge has reached the end of its service life.

Regular maintenance helps:

• Maintain filtration performance
• Preserve good water flow
• Protect the filter housing
• Ensure the system continues operating efficiently

Using the correct replacement cartridge for your system is important, as different cartridges are designed to perform different filtration functions.

Why Trust Fountain Filters

Choosing a whole house water filter isn't simply about selecting the biggest housing or the highest flow rate. The most effective system is one that's matched to your property's plumbing, your household's water usage and the improvements you want to make to your mains water.

At Fountain Filters, we specialise in water filtration and understand that every property has different requirements. Whether you're filtering the incoming mains supply to reduce sediment, improve taste and odour or protect plumbing and appliances, we're here to help you choose the right solution.

When you buy from Fountain Filters, you benefit from:

• Specialist knowledge of domestic and commercial water filtration
• Carefully selected products from trusted manufacturers
• Friendly, expert advice before and after your purchase
• Genuine replacement cartridges and ongoing product support
• UK based customer service from a team that understands water filtration

If you're unsure which whole house filtration system is right for your property, we're always happy to help you compare the options and make an informed decision.

FAQ

What is a mains water filter?

A mains water filter, also known as a whole house water filter, is installed on the incoming water supply where it enters your property. It filters the water before it is distributed around your home, helping to improve water quality at every cold water outlet.

What is the difference between a mains water filter and a water purifier?

A mains water filter treats the incoming water supply to provide filtered water throughout your property. A water purifier is usually installed beneath the kitchen sink or at a single tap to improve the quality of your drinking water. If your main goal is cleaner water throughout your home, a mains water filter is generally the better choice. If you're primarily looking to improve the water you drink, a water purifier may be more suitable.

Will a whole house water filter reduce my water pressure?

A correctly sized mains water filter should have minimal impact on water pressure during normal household use. It's important to choose a system with an appropriate flow rate for your property, particularly if multiple taps, showers or appliances are likely to be used at the same time.

What size mains water filter do I need?

The right size depends on your property's water demand, the number of bathrooms, the expected flow rate and the type of filtration required. Larger homes or commercial premises often require higher-capacity systems to maintain good flow while providing effective filtration.

Can I install a mains water filter on a combi boiler system?

Yes. Many whole house water filters are suitable for installation on properties with combi boilers or other sealed, pressurised systems. The filter is typically installed on the incoming cold water main before it is distributed throughout the property. If you're unsure which system is suitable for your plumbing, we're happy to offer advice.

How often should I replace the filter cartridge?

Replacement intervals depend on the filter cartridge, your household water consumption and the quality of your incoming water supply. Following the manufacturer's recommended replacement schedule will help maintain filtration performance and water flow.

Do mains water filters remove limescale?

Standard mains water filters are not designed to soften hard water or remove dissolved limescale. If hard water is your main concern, a water softener or specialist scale reduction system may be a more suitable solution. Some whole house systems can, however, be fitted with cartridges designed to help reduce the effects of scale, depending on the application.

Need Help Choosing the Right Mains Water Filter?

Choosing the right whole house water filter doesn't have to be complicated. Whether you're looking to reduce sediment, improve taste and odour or protect your home's plumbing and appliances, we're here to help.

If you're unsure which system is best for your property, contact the Fountain Filters team for friendly, expert advice. We'll help you compare the available options and recommend a filtration system that's suited to your water supply and household requirements.

* Watts components are sometimes replaced with other similar quality items due to supply chain issues. Brassware and other plumbing accessories are sourced from UK suppliers.