Skip to content

Before your visit

Preparing for tap and under-sink filter fitting

The product, access and compatibility details to gather for taps, showerheads and under-sink filter systems.

On this page

The short answer

Send the existing fitting, replacement model and clear photos of accessible connections and cupboard space. Tap holes, water-supply requirements, isolation, filter compatibility and future cartridge access all affect the work. Our filter scope is under-sink and filter-tap systems only, excluding reverse osmosis, whole-house systems and water softeners.

A fitting that looks similar can have different connection or supply requirements. You do not need to disconnect a tap or identify every valve yourself. Product links and views of the accessible space are a useful starting point.

What details are needed to replace a kitchen, basin or bath tap?

Send the replacement model and show the current tap and its mounting area. The number and arrangement of holes, access to the underside, existing pipework and the replacement tap's operating requirements all affect compatibility. A bath tap with no accessible underside is a different job from a kitchen tap reached through a clear cupboard.

A matching appearance does not prove a matching installation. A single-hole mixer, separate pillar taps and a wall-mounted fitting have different mounting arrangements. Even with the same hole pattern, the spout needs suitable reach over the basin and the underside must accommodate the fixing and connections. Share the replacement's dimensional drawing as well as its photograph.

Mention any known low-pressure supply, a problem with isolation, corrosion or an existing leak. The replacement's required supply pressure needs comparing with the actual system. Weak flow at every outlet suggests a different enquiry from reduced flow at one tap only; describe the pattern without dismantling the fitting. Existing low flow should not automatically be blamed on the new tap specification.

If worktop or sink drilling is needed, identify the material and discuss that work explicitly. A new hole is not automatically included in an ordinary tap replacement. Our tap and shower fitting page explains the scope to include in the enquiry.

What about a showerhead or hose replacement?

Provide the showerhead or hose model and the existing shower details where known. Connection compatibility and the shower manufacturer's requirements matter, particularly if the replacement changes the flow or operating arrangement.

A showerhead or hose change does not imply replacement of an electric shower, power shower or concealed valve. Describe those jobs separately before buying parts or arranging work. A shower hose that can reach another water source may also need the installation's backflow protection considered; it is not just a question of whether the thread fits. Water Regs UK explains the general fitting requirements.

Will an under-sink filter work with my existing tap?

An under-sink filter works with an existing tap only when the system is designed for that connection and flow arrangement. A separate drinking-water tap needs its own mounting position; a compatible three-way tap combines hot, cold and a filtered-water outlet in one fitting. A standard mixer is not automatically interchangeable with either arrangement.

Share the make, model, product link and instructions, plus a cupboard photo. Space is needed for the fitted system and for the cartridge to be serviced later. Manufacturer requirements may include supply conditions, mounting position, commissioning and specific compatible parts; a cupboard that fits the housing tightly may leave no usable service clearance.

A filter needs servicing space as well as fitting space

A. Compatible tap
Use the tap arrangement approved for the chosen system.
B. Reachable isolation
Access to the appropriate valves must remain usable.
C. Cartridge removal space
Leave the servicing space the model requires. Removal direction and clearance vary.

One illustrative under-sink arrangement, not a plumbing layout. Follow the actual system's installation and maintenance requirements.

Plan for both the fitted housing and the movement needed to replace its cartridge. This is a layout concept, not a universal clearance dimension. The exact system's mounting and maintenance instructions determine the usable space.
  • Housing space: the unit fits without fouling the sink bowl, waste trap, shelves or cupboard door.
  • Service space: the cartridge or sump can follow its required removal path and the release mechanism remains reachable.
  • Access: the relevant isolation and connections remain accessible for the agreed servicing arrangement.
  • Tap space: any separate outlet or replacement mixer fits the sink or worktop and has suitable clearance below.

Orientation is product-specific. For example, BRITA's mypure P1 allows horizontal or vertical cartridge mounting. That flexibility must not be assumed for a different housing. A cupboard photo with approximate clear dimensions is more useful than its overall width alone.

We currently cover under-sink and filter-tap installation and maintenance. Reverse osmosis, whole-house treatment and water softeners are outside this offer.

How do I prepare for a filter cartridge change?

Find the system and cartridge model if the labels are visible, and note when the cartridge was last changed. Keep the replacement in its packaging. A similar-looking cartridge is not confirmation of compatibility, and replacement intervals depend on the particular product and usage rather than a universal schedule.

BRITA's mypure P1 manual, for example, sets a maximum cartridge use period of 12 months, with capacity affected by the selected setting and water conditions. That is an upper limit for that system, not an annual rule for every filter. The applicable time limit, rated capacity and any instructions after prolonged non-use all belong in the maintenance plan. Use the exact BRITA manual only if it matches your model.

Tell us about any leak, reduced flow, unusual taste or overdue maintenance. Those details help distinguish a planned cartridge replacement from a fault requiring assessment. Installation or servicing does not establish that water has been laboratory tested, and a general filter does not remove every possible contaminant.

A maintenance record should identify the fitted system, cartridge code, replacement date and next time or capacity limit. Reduced filtered-water flow with normal unfiltered flow is different from weak flow throughout the property; a leak also needs a fault enquiry, not just a cartridge order. Taste alone cannot confirm that a cartridge still meets all its treatment claims.

The Drinking Water Inspectorate's domestic-filter guidance explains that public supplies generally do not need extra treatment for health protection and that filters need appropriate maintenance. Suspected supply problems should be discussed with the water company rather than assumed to need a filter.

What needs to be cleared before the visit?

Empty the working cupboard of loose belongings and cleaning products, leaving the existing fittings undisturbed. Tell us about access panels, appliances, shelves or storage that obstruct the connections. Keep the instructions and complete supplied parts available.

Do not force a seized valve or disconnect pipework to prepare for the visit. If there is an active leak, describe it when making contact; an ordinary future fitting request should not be treated as a confirmed emergency response. The quote-request guide lists the remaining information that helps agree the job.

Common questions

Sources and further reading

Product instructions apply to the particular fitting or finish. These references explain the general distinctions used here.

  1. Water Regs UK: water fittings requirements in England
  2. Drinking Water Inspectorate: domestic water filters and softeners
  3. BRITA mypure P1: permitted cartridge orientation
  4. BRITA mypure P1 manual: model-specific cartridge maintenance

Have a fitting or filter in mind?

Send the product link and a view of the existing space. We can discuss what needs checking before the work is agreed.

Discuss your fitting
Get a quote