How to Fix a Leaking Tap in Redhill - A Complete Home Repair Guide

Published August 2026 | Leaking Tap Repair

This guide covers everything you need to know to diagnose and repair a dripping or leaking tap in your home, from identifying the type of tap you have to replacing worn washers and O-rings. It's aimed at Redhill homeowners who are comfortable doing basic DIY and want to understand the process before picking up a spanner - or before deciding whether to call a plumber.

Before You Start - Safety First

Before you touch anything under the sink or behind a tap, you need to isolate the water supply. This is the single most important step and the one most people skip, only to end up with water spraying across the bathroom. Every tap in your home is fed by either the mains supply or your cold water storage tank in the loft, and you must cut that supply off before dismantling the tap head.

Look under the sink for an isolator valve on the pipe feeding the tap. These are small inline valves, usually slotted brass fittings. Turn the slot 90 degrees with a flathead screwdriver so it sits across the pipe rather than inline with it - that means it's closed. If there's no isolator valve, you'll need to turn off the stopcock, which is usually found under the kitchen sink or where the water main enters the property. In older Redhill properties, this is sometimes in the airing cupboard or near the front of the building.

Once the supply is isolated, open the tap fully to release any residual pressure in the line and drain the remaining water. Put a towel under your work area and keep a bucket handy. Don't assume the water is fully off until you've seen flow slow to nothing.

What You Will Need

Getting your tools together before you start will save you a frustrating mid-job trip to the hardware shop. Here's what you'll typically need for most tap repairs:

Tools:

• Adjustable spanner or basin wrench
• Flathead and crosshead screwdrivers
• Allen key set (many modern mixer taps use grub screws)
• Pliers
• PTFE tape
• Cloth or old towel

Materials:

• Replacement washers (common sizes: 1/2 inch and 3/4 inch - buy a mixed pack)
• O-ring set (again, a mixed pack covers most scenarios)
• Tap grease (silicone-based, available from any plumber's merchant)
• Replacement cartridge if you have a ceramic disc tap (identify your tap brand first - Bristan, Grohe, Ideal Standard, and Pegler are common in Surrey homes)

Time estimate: Allow 45 minutes to 1.5 hours for a first attempt. An experienced plumber will typically complete a washer replacement in 20-30 minutes, but working around the tight spaces under a basin or kitchen sink takes time if you're not used to it.

Parts will cost you between 2 and 15 pounds for washers, O-rings, and PTFE tape. A replacement ceramic cartridge can run between 8 and 40 pounds depending on the brand and tap model.

Step-by-Step Instructions

Step 1 - Identify What Type of Tap You Have

The repair method depends entirely on tap type. There are three common types found in Redhill homes:

• Traditional pillar taps - separate hot and cold taps with a rising spindle. These use rubber washers and are the easiest to fix.
• Ceramic disc taps - quarter-turn taps that use a ceramic cartridge instead of a rubber washer. Very common in homes built after the 1990s.
• Mixer taps with a single lever or separate handles - these vary widely depending on the manufacturer. Some use ceramic cartridges, others use O-rings or ball valves.

If you're unsure, take a photo of your tap and note the brand if visible. Many mixer taps used by builders across Surrey have the manufacturer name on the spout or under the handle cap.

Step 2 - Remove the Tap Handle

Most tap handles are held on by a screw hidden under a decorative cap or cover. Use a flathead screwdriver to pop off the plastic cap on top of the handle - it's usually just press-fitted. Underneath you'll find either a crosshead or Phillips screw. Remove it and the handle should pull straight off. If it's stuck, a gentle twisting motion usually frees it. Don't force it with a lever - you risk cracking the tap body.

On some modern mixer taps, there's no cap - instead, look for a small grub screw on the side or rear of the handle. You'll need an Allen key for these, typically 2.5mm or 3mm.

Step 3 - Remove the Headgear or Cartridge

With the handle off, you'll see the tap headgear - the assembly that holds the washer or ceramic cartridge in place. On a traditional pillar tap this is a hexagonal brass nut that you unscrew anticlockwise with your adjustable spanner. Protect the chrome with a cloth to avoid scratching it.

On a ceramic disc tap, the cartridge will be visible once the handle is removed. Some cartridges lift straight out; others are retained by a clip or small nut. Note which way the cartridge is oriented before removing it - it needs to go back in the same way.

Step 4 - Replace the Washer or O-Ring

For a traditional pillar tap, the rubber washer sits at the base of the headgear. It's held in place by a small brass nut. Unscrew this nut (you may need pliers), remove the old washer, and press the new one into place. It should be a snug fit. If the washer looks swollen, cracked, or deformed, that's almost certainly your source of the drip.

If your tap is leaking around the base of the spout or around the handle rather than from the spout itself, the issue is usually a worn O-ring rather than the washer. O-rings are rubber rings that sit in grooves around the spindle or spout body. Roll the old one off, coat the new one lightly in silicone tap grease, and roll it into the groove.

For a ceramic cartridge, compare your old cartridge to the replacement before fitting. The notches and orientation points need to match. If you're in Redhill and can't find the correct cartridge locally, most plumbing merchants in the Surrey area carry common sizes, and many tap manufacturers can supply replacements direct.

Step 5 - Reassemble the Tap

Reassembly is the reverse of removal. Apply a small amount of PTFE tape to any threaded connections before screwing them back together. Don't overtighten - brass fittings are relatively soft and can strip or crack if you go too hard. Firm hand-tight plus a quarter turn with the spanner is typically enough.

Refit the handle, replace the decorative cap, and make sure everything sits flush and moves smoothly before turning the water back on.

Step 6 - Restore the Water Supply and Test

Turn your isolator valve back to the open position (slot inline with the pipe) or reopen the stopcock. Let the tap fill slowly - you may hear some air in the lines for the first few seconds, which is normal. Open the tap and check for leaks at the handle, the base of the spout, and at the tap body itself. Run both hot and cold through and watch for a few minutes before declaring it fixed.

A light smear of water around the headgear immediately after turning on is normal and will dry quickly. A steady drip or seeping water means something isn't seated correctly - turn off the supply and investigate before leaving it.

Step 7 - Check Your Water Pressure

While you have everything apart, it's worth checking whether low or uneven water pressure is contributing to the problem. Taps in Redhill properties are supplied at mains pressure (commonly 1 to 3 bar) or via a gravity-fed system from a loft tank (typically 0.1 to 1 bar). Low pressure can cause taps to drip intermittently even after a repair, because the washer isn't being held firmly against the seat. If pressure seems low, that's a separate issue worth investigating.

Our engineers at Voltrade often use the GoFIX diagnostic tool during a callout to log initial pressure readings, which helps identify whether a recurring drip is a tap problem or a system pressure problem - a distinction that saves homeowners from repeat call-outs.

What to Do If This Does Not Fix It

If you've replaced the washer and the tap is still dripping, the problem is likely the tap seat - the brass surface that the washer presses against to form a seal. Over time, limescale and grit wear a groove into the seat, and no washer will seal against it properly no matter how new it is. This is particularly common in Surrey's hard water areas, including parts of Redhill where limescale build-up in tap fittings is a frequent issue.

You can resurface a tap seat with a tool called a tap reseating tool or tap seat grinder, which costs around 15 to 30 pounds and works by grinding the seat flat again. It's a bit fiddly but perfectly doable as a DIY job. Alternatively, nylon seat inserts are available that sit over a damaged seat and provide a fresh sealing surface without grinding.

If you have a ceramic disc tap and you've replaced the cartridge but it's still leaking, double-check that the cartridge is the correct one for your tap model. An incorrect cartridge that's slightly the wrong diameter or has the ports in the wrong position won't seal properly and will cause an immediate drip or a slow seep around the body.

When to Stop and Call a Professional

Not every tap repair needs to end with a plumber, but there are situations where calling one in is genuinely the better option and will save you money in the long run.

Call a plumber if you find any of the following:

• The tap body is cracked or visibly corroded - this cannot be repaired and the tap needs replacing
• You can't isolate the water supply and the repair requires cutting pipe or modifying the supply line
• The leak is coming from the supply pipes behind the wall or under the floor rather than the tap itself
• You've replaced the cartridge or washer twice and it's still leaking - there's likely a bigger underlying issue
• The tap has seized completely and you risk damaging the basin or worktop trying to remove it

A local Redhill plumber will typically charge between 60 and 120 pounds per hour for callout work, and a tap repair or replacement usually takes one to two hours. A full tap replacement including labour and a mid-range tap fitting will commonly run between 150 and 300 pounds depending on the tap chosen and any access complications. These are rough benchmarks for the Surrey area - costs vary based on the specific job.

If you're not confident at any stage, stop. Water damage from a poorly reassembled tap can cause far more expensive repairs than the call-out fee you were trying to avoid.

Questions About This Process

How much does a plumber charge to fix a leaking tap in Redhill?

Most Redhill plumbers charge between 60 and 100 pounds per hour, and a standard washer or cartridge replacement typically takes 30 to 60 minutes on site. Expect to pay between 80 and 150 pounds for a simple repair, including parts. If the tap needs replacing entirely, budget between 150 and 300 pounds depending on the tap model you choose and the complexity of the installation. Always confirm whether the call-out fee is included in the hourly rate before booking.

Can I fix a dripping tap without turning off the mains water supply?

In theory, yes - if you have working isolator valves directly under the tap and they shut off the flow completely. In practice, many older isolator valves in Surrey properties are corroded or partially blocked and don't fully close, which means you'll get a trickle of water throughout the repair. It's always safer to turn off the mains stopcock for peace of mind. If your isolator valves are stiff or appear to be seized, don't force them - call a plumber who can isolate the supply safely before anything else is touched.

Why does my tap drip only when it is turned off?

A tap that drips only when shut off almost always has a worn or degraded washer or ceramic cartridge. When the tap is open, water flows freely. When you close it, the washer or cartridge is supposed to press against the seat and form a watertight seal - but if the washer is cracked, flattened, or the seat is damaged, that seal is incomplete and water drips through. In hard water areas like Redhill and much of Surrey, limescale accelerates this wear considerably, meaning washers and cartridges may need replacing more frequently than in softer water regions.