If you've grown tired of buying bottled water or refilling a countertop filter jug, a filter tap is one of the smartest upgrades you can make to your kitchen. Clean, great-tasting water comes straight from your tap, no jugs, no plastic waste, no waiting.
The challenge most buyers face isn't whether to get a filter tap. It's knowing which type to choose. The two most popular options, the 3-way filter tap and the 4-in-1 kitchen tap, look similar but work very differently and suit different households. This guide explains how each works, compares them honestly, and gives you everything you need to choose the right one for your kitchen.
What Is a Filter Tap?
A filter tap is a kitchen tap connected to an under-sink filtration system. Water from your mains supply passes through a cartridge, typically activated carbon, before being dispensed, removing chlorine, sediment, organic compounds, and other impurities that affect taste and odour.
Unlike a standard mixer tap, a filter tap delivers a separate stream of filtered water through a dedicated flow path. This keeps filtered water entirely separate from your regular hot and cold supply, so there's no cross-contamination.
Filter taps come in two main configurations: 3-way filter taps, which add filtered cold water to your standard hot and cold supply, and 4-in-1 kitchen taps, which add both filtered cold and instant boiling water.
3-Way Filter Taps Explained
A 3-way filter tap, sometimes called a triflow tap, combines hot water, cold water, and filtered drinking water in a single tap body. Despite sharing one spout, the filtered water travels through a completely separate internal chamber, keeping it isolated from your mains supply at all times.
This dual-flow "tube within a tube" design is the key engineering feature. The filtered water is delivered at ambient (room) temperature; it's not chilled or heated, simply purified cold water from the mains.
Handle configurations vary by model. Some 3-way taps use three separate levers (one each for hot, cold, and filtered), while others use two levers — a combined hot/cold mixer plus a dedicated filtered water lever. Both work equally well, and it really comes down to personal preference.
Its worth noting that most 3-way taps require a minimum mains pressure of 0.5 bar and are not suitable for gravity-fed systems without a pump.
What Does a 3-Way Filter Tap Remove?
The activated carbon cartridge in a standard 3-way filter system removes:
- Chlorine and chloramine (the main cause of "tap water taste")
- Sediment and particulates
- Organic compounds and herbicide traces
- Heavy metals such as lead and copper (with some cartridge grades)
It does not soften hard water or remove dissolved minerals; for that, you'd need a water softener or reverse osmosis system alongside your filter tap.
4-in-1 Kitchen Taps Explained
A 4-in-1 kitchen tap does everything a 3-way tap does, and adds instant boiling water as a fourth function. In a single tap, you get:
- Regular hot water (from your boiler)
- Regular cold water (from the mains)
- Filtered cold drinking water
- Instant boiling water (98–100°C, from an under-sink tank)
The boiling function is powered by a compact insulated tank installed in your under-sink cupboard. It heats and holds water at near-boiling temperature, delivering it on demand. A spring-loaded safety handle prevents accidental activation, you press and twist to release the boiling flow.
4-in-1 taps require more under-sink space than a 3-way tap (for the boiling tank), and they're a more significant investment. But for households that regularly boil a kettle for tea, coffee, or cooking, the convenience gain is substantial.
3-Way vs 4-in-1 Filter Taps — Which Should You Choose?
Here's a direct comparison:
| 3-Way Filter Tap | 4-in-1 Kitchen Tap | |
|---|---|---|
| Functions | Hot, cold, filtered cold | Hot, cold, filtered cold, boiling |
| Price range | £150–£400 | £400–£1,000+ |
| Under-sink requirement | Filter cartridge only | Cartridge + boiling tank |
| Installation complexity | Moderate | More involved |
| Running costs | Cartridge: ~£30–50/yr | Cartridge + electricity: ~£60–100/yr |
| Best for | Clean drinking water on tap | Removing the kettle entirely |
Choose a 3-way filter tap if:
- You mainly want better-tasting drinking water
- You have limited under-sink space
- You're working to a tighter budget
- You already have a kettle you're happy with
Choose a 4-in-1 tap if:
- You boil a kettle multiple times a day
- You want to clear the worktop and remove the kettle entirely
- You're renovating your kitchen and want a single premium solution
- Budget allows for a higher upfront investment
How to Choose a Filter Tap for Your Kitchen
Water pressure: Most filter taps require a minimum of 0.5 bar. If you have a gravity-fed system (common in older UK homes), check compatibility or budget for a pump. Maximum pressure is typically around 10–12 bar — most UK homes are well within this.
Hard water areas: If you're in a hard water area (most of the South East and Midlands), your filter cartridge will clog faster and need replacing more frequently. Some brands offer hard water-specific cartridges — worth specifying at the point of purchase.
Tap hole size: Filter taps typically require a 35mm tap hole in your sink or worktop. Most UK sinks have a pre-drilled hole suitable for standard mixers, but check your sink specification before buying.
Finish: Match your filter tap to your sink, handles, and kitchen hardware. The most popular finishes in UK kitchens are:
- Chrome — classic, easy to maintain, widely available
- Matt black — contemporary, hides watermarks well
- Brushed brass / brushed nickel — warm, on-trend, premium feel
Browse our full filter tap collection
Filter Tap Costs & Running Costs
Tap purchase price:
- 3-way filter taps: £150–£400 depending on brand and finish
- 4-in-1 kitchen taps: £400–£1,000+ for premium models with boiling function
Ongoing running costs:
- Filter cartridge replacement: every 6–12 months, costing roughly £30–£60 per cartridge
- For 4-in-1 taps, add electricity for the boiling tank: approximately £20–40/year, depending on usage
The average UK household spending £5–£10/week on bottled water spends £250–£500 a year. A filter tap pays for itself in two to three years, with no plastic waste.
Top Filter Tap Brands at The Tap Collection
Triflow Concepts — The original pioneers of the 3-way tap, established in 1978 and makers of the world's first patented filter tap. Triflow's multi-stage filtration system — ceramic, silver impregnation, activated carbon, and zeolite — is among the most thorough available, and their taps are manufactured in the UK. A benchmark choice for quality-first buyers. Browse Triflow Concepts taps
Abode — A well-established British brand known for combining thoughtful design with everyday practicality, Abode’s filter tap range is built around simplicity, reliability, and modern styling. With a strong focus on clean lines and versatile finishes, their taps integrate seamlessly into both contemporary and classic kitchens. Backed by dependable UK distribution and easy-to-source replacement filters, Abode is a solid choice for buyers seeking a balance of design, performance, and long-term usability. Browse Abode taps
Pronteau (by Abode) — One of the most widely specified filter tap ranges in the UK. Pronteau covers both 3-way and 4-in-1 configurations, with a strong selection of finishes and a clean, contemporary aesthetic. Reliable cartridge supply and straightforward installation make it a consistently popular choice. Browse Pronteau taps
INTU — INTU's 4-in-1 boiling water taps are an excellent entry point into instant boiling water with filtration, offering a competitive price point alongside a modern design. Well suited to buyers making the move away from the kettle for the first time. Browse INTU taps
Grohe Blue — Grohe's Blue range focuses on filtration excellence, using a five-stage process to remove chlorine, limescale, and fine particles. Available in a range of refined finishes, the Grohe Blue Pure series is a strong 3-way option for buyers who want German engineering and a design-led aesthetic. Browse Grohe filter taps
Installation — What to Expect
A filter tap installation is more involved than fitting a standard mixer, but is within reach of a competent DIYer. Here's what's required:
- An available tap hole in your sink or worktop (35mm standard)
- Under-sink space for the filter cartridge housing (3-way) or filter housing plus boiling tank (4-in-1)
- A connection to the cold mains supply using the supplied fittings
- For 4-in-1 taps: a nearby power outlet for the boiling tank
Most manufacturers supply full fitting instructions and the necessary connectors. For 4-in-1 systems in particular, a professional plumber installation is recommended — especially if you need to drill a new tap hole or the under-sink configuration is tight.
Budget approximately £100–£200 for a plumber fitting, depending on your location and whether additional work is needed.
FAQ
Are filter taps worth it in the UK?
Yes — particularly if you drink a lot of tap water and are conscious of the cost and environmental impact of bottled water. The ongoing cost of cartridge replacement is modest, and the water quality improvement is noticeable, especially in hard water or chlorine-heavy supply areas.
How long do filter cartridges last?
Most cartridges last 6–12 months, depending on household usage and water hardness. In hard water areas (such as London and the South East), expect to change cartridges closer to every 6 months. Manufacturers usually send replacement reminders.
Do filter taps work with hard water?
Yes, but carbon filtration doesn't soften hard water — it improves taste and removes chlorine. If limescale and hardness are a concern, consider pairing a filter tap with a water softener or choosing a tap compatible with a reverse osmosis system.
Can I fit a filter tap myself?
A 3-way filter tap can be a DIY installation if you're comfortable with basic plumbing. A 4-in-1 tap with a boiling tank is best installed by a qualified plumber, as it involves electrical connections and precise pressure balancing.
What's the difference between a filter tap and a boiling water tap?
A filter tap (3-way) delivers filtered cold drinking water alongside your regular hot and cold. A boiling water tap — or 4-in-1 tap — adds instant boiling water as a fourth function. Both filter the water; only the 4-in-1 replaces your kettle. Explore boiling water taps
Conclusion
Filter taps are among the most practical kitchen upgrades available, giving you clean, great-tasting drinking water without the ongoing cost or waste of bottled water. If you want filtered cold water alongside your standard supply, a 3-way filter tap is a straightforward, cost-effective solution. If you're ready to go further and ditch the kettle, a 4-in-1 kitchen tap combines everything in one sleek fitting.
Browse The Tap Collection's full range of filter taps — from Triflow Concepts 3-way systems to Quooker and INTU 4-in-1 taps — with free UK delivery and expert advice available if you need help choosing.