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Water filter taps: three-way, separate and mixer taps
Keep one mixer tap or add a separate drinking-water tap: the right choice depends on your filter, the sink and your water pressure. Compare Doulton and Aquaphor taps, their UK prices and the fittings they need. The filters are bought separately, and these taps do not boil water.
Photo: Doulton
Compare filter taps
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Photo: Doulton
Doulton three-way mixer tap
Three-way mixer tap · W2313070-01
£199.95[1]
For the tap alone. The system, installation and any plumber are extra.
One tap body with separate hot, cold and filtered water paths. It replaces your mixer tap rather than adding a second tap, and it does not boil water.
See the three-way tap at Doulton Affiliate link
In the box: A mixer tap with three separate water paths[1].
- Works with
- The Kingfisher, HIP DUO and HIP TRIO, and the HIS. Doulton says it is not for its countertop or gravity systems.[1]
- Pressure
- Doulton recommends a balanced 1.5 to 6 bar inlet.[1]
- Not a boiling tap
- The third path carries filtered water. It does not boil water.[1]
Think twice if you want hot filtered water or boiling water, or need to keep your existing mixer tap, or have no inlet pressure figure for the hot and cold supplies.
Doulton pillar tap
Separate filter tap · W2313062-01
£44.95[2]
For the tap alone.
A small separate tap that delivers only filtered water. It sits beside your existing mixer tap, so it needs its own tap hole.
In the box: A separate pillar tap for filtered water[2].
- Needs
- A tap hole of its own, so check the sink or worktop before you order.[2]
- Used in our comparison
- Included in the £299.90 Kingfisher total and the £349.90 HIP DUO total.[2]
Think twice if you cannot or must not drill the sink or worktop, or have no spare hole.
Photo: Aquaphor
Aquaphor C125 filter tap
Three-way mixer tap · C125
For the tap alone. The Crystal and C125 together are a separate £229.99 bundle, not the sum of the Crystal at £129.99 and this tap.
A stainless steel mixer with hot, cold and filtered water. The filter is separate, so the tap is only half of a set-up.
In the box: A stainless steel mixer tap; the filter is separate[3].
- Pressure and temperature
- Maximum 6.3 bar. Hot water up to 75 °C; filtered water 4 to 38 °C.[5]
- Fitting
- Mounts through a 35 mm hole. Hot and cold use G1/2 hoses; filtered water uses a G3/8 connection with the included JG1/4 adapter.[5]
- Works with
- Aquaphor’s Crystal in the bundle. Check the full system’s pressure and fittings against the manual before you pair it with anything else. We make no claim that it fits other makers’ systems, Doulton’s included.[3][4][5]
- The bundle
- The Crystal with the C125 is £229.99. The standard Crystal at £129.99 includes a standard drinking tap, not the C125.[4][6]
Think twice if you want to pair it with another maker’s filter, or cannot meet the 6.3 bar limit without a pressure reducer, or do not already have a suitable 35 mm hole: reusing one is not guaranteed to need no work.
Side by side
| Product | What it does | Price | Works with | Check first |
|---|---|---|---|---|
| Doulton three-way mixer tap | One body: hot, cold and filtered cold[1] | £199.95[1] | Doulton Kingfisher, HIS, HIP DUO, HIP TRIO[1] | 1.5 to 6 bar balanced inlet; not for countertop or gravity systems[1] |
| Doulton pillar tap | A second tap for filtered water[2] | £44.95[2] | Doulton under-sink systems sold without a tap[2] | A tap hole of its own[2] |
| Aquaphor C125 filter tap | Stainless steel mixer: hot, cold and filtered[3] | £169.99; Crystal and C125 bundle £229.99[3][4] | Aquaphor Crystal in the bundle; other systems not verified[4] | 6.3 bar maximum; a 35 mm hole; G1/2 and G3/8 connections[5] |
Prices are the sellers’ displayed UK prices on 16 October 2026, for the tap alone, and fitting is extra.
Three ways to get filtered water at a tap
A separate tap gives filtered water its own spout and needs its own hole. A three-way mixer replaces your mixer tap and carries hot, cold and filtered water in one body. The third option is to filter through the tap you already have, which avoids a new hole but depends on the filter and the tap.
A separate filter tap takes the cold supply through an under-sink filter to a second tap that needs its own hole. A three-way mixer tap takes hot, cold and filtered pipes to one tap body with three paths. Your existing tap can be fed through a filter connection or a diverter, which needs no new hole but depends on the model and on the tap.
- You have a spare hole or can drill oneA separate filter tap such as the pillar tap, or the tap supplied in a kit.
- You are replacing the mixer tap anywayA three-way mixer, but only one the filter’s maker says it works with.
- You can’t or mustn’t change the tapFilter through the existing tap with a system the maker says allows it. Fitting without drilling explains what that does and doesn’t mean.
Systems with a tap, or using yours
Many under-sink kits include a tap or use the one you have, so you may not need to buy one separately. This table shows which, from the sources behind our under-sink comparison.
| System | Which tap | Check first |
|---|---|---|
| Doulton Kingfisher and HIP DUO[1] | None included: a pillar tap at £44.95 or the three-way mixer tap at £199.95[2][1] | Pillar tap needs its own hole; three-way tap needs 1.5 to 6 bar balanced inlet[2][1] |
| Aquaphor Crystal Solo[7] | Its own drinking tap, included[7] | Needs a tap hole[7] |
| Aquaphor Crystal three-stage[6] | A standard drinking tap, included; not the C125[6] | Needs a tap hole; maximum 6.3 bar[8] |
| UK Water Filters anti-scale kit[9] | Its own tap, included[9] | An existing mixer tap is not compatible[9] |
| Waterdrop WD-10UA[10] | Your existing tap[10] | Connects to the existing cold line; pressure range 10 to 125 psi[10] |
| Doulton countertop system[11] | Your existing tap, through a diverter[11] | A compatible thread or a removable aerator[11] |
How to choose
- Start with the filter, not the tap. A three-way tap is not universal. Doulton’s works with its Kingfisher, HIS, HIP DUO and HIP TRIO, and not with its countertop or gravity systems. We have not verified that Aquaphor’s C125 fits any system except Aquaphor’s Crystal in the bundle.
- Check pressure. Doulton recommends a balanced 1.5 to 6 bar inlet for its three-way tap, and Aquaphor’s manual sets a 6.3 bar maximum for the C125. Check the full system, not only the tap.
- Check the hole and hoses. The C125 mounts through a 35 mm hole and uses G1/2 hoses for hot and cold and a G3/8 connection for filtered water. Reusing a suitable existing hole avoids drilling, but it does not guarantee no fitting work.
- Count the whole price. Add the tap to the system: the Kingfisher with the pillar tap is £299.90, and the HIP DUO with the three-way tap is £504.90, before fitting. The matched totals set each combination out.
Common questions
What is a three-way filter tap?
One tap body with separate hot, cold and filtered water paths. It replaces your mixer tap instead of adding a second tap.
Does a filter tap boil water?
No. Doulton says its three-way tap does not boil water. If that is what you want, see boiling water taps.
Can I fit any three-way tap to any filter?
No. Compatibility is set by the maker for each system, and we make no universal claim. Check the pressure, hose and thread details for the exact filter and tap.
Do I need to drill for a filter tap?
A separate tap needs a hole of its own. A three-way mixer or a filter that uses your existing tap may not, but “no drilling” does not mean no changes to the pipework. See fitting without drilling.
Related guides
- Under-sink water filters compared with matched totals for each tap choice.
- Fitting an under-sink filter without drilling and what installation costs.
- Replacement cartridges for the systems these taps work with.
Sources
- Doulton: three-way mixer tap read 16 October 2026
- Doulton: pillar tap read 16 October 2026
- Aquaphor: C125 filter tap read 16 October 2026
- Aquaphor: Crystal with C125 tap bundle read 16 October 2026
- Aquaphor: C125 tap instructions (PDF) read 16 October 2026
- Aquaphor: Crystal three-stage under-counter purifier read 16 October 2026
- Aquaphor: Crystal Solo read 16 October 2026
- Aquaphor: Crystal instructions (PDF) read 16 October 2026
- UK Water Filters: Anti-Scale under-sink kit read 16 October 2026
- Waterdrop: WD-10UA direct-connect system read 16 October 2026
- Doulton: countertop system with Biotect Ultra read 16 October 2026
Read on 16 October 2026 from the makers’ own pages and instructions. How we check.