A dripping tap is one of those jobs people put off because it feels harmless. One drop every few seconds does not look like much, especially compared with a burst pipe or a blocked toilet, but it can still add up on a water meter and it often gets worse rather than better.
In London homes we also see the damage around the drip before the customer notices the bill. Water marks on a vanity unit, a swollen worktop near the tap hole, limescale staining in the basin, or a slow leak running down the back of a bath panel can turn a small washer or cartridge job into a repair involving carpentry and decorating.
So, does a dripping tap actually cost you if not fixed quickly? Yes, it can. The actual cost depends on how fast it is dripping, whether it is hot or cold water, whether the property is metered, and whether the leak is only from the spout or also from the body of the tap.
Why a Small Drip Still Matters in a London Property
A typical slow drip can waste roughly 10 to 30 litres a day. A faster drip or thin running trickle can waste 100 litres a day or more. On a metered supply, that can mean around £30 to £250+ a year in wasted water and wastewater charges, and more if it is hot water because you are also paying to heat it.
The bigger issue is that a dripping tap is usually a symptom of wear. In traditional pillar taps it is often a perished washer or damaged seat. In modern mixer taps it is commonly a ceramic cartridge, O-ring, flexi hose, or gland seal. London hard water does not help because limescale builds up around cartridges, aerators and spindles, especially in older flats and Victorian or Edwardian conversions with mixed-age plumbing.
There is also a practical landlord point. A tenant may report a dripping tap early, but if it is left for weeks it can stain sanitaryware, damage laminated units, and encourage mould around silicone joints. A small repair that might have cost £90 to £180 during a normal weekday visit can become a larger maintenance job if water has been getting into timber or plasterboard.
Confirm Where the Tap Is Leaking
Start by finding the exact leak point. A drip from the end of the spout normally points to an internal washer, valve or ceramic cartridge. Water around the base of the tap can mean a failed O-ring, loose fixing, failed sealant, or water tracking under the tap after use.
Dry the area with kitchen towel, then run the tap and watch it for a few minutes. Check under the sink with a torch, especially where the flexible hoses connect to the tap tails and isolation valves. If you see water below, do not assume it is only a dripping spout, because a hidden leak under a basin can damage a cupboard long before it reaches the floor.
Measure the Drip Before You Guess the Cost
If you are on a water meter, put a measuring jug under the tap for 10 minutes and multiply the result. For example, 150 ml in 10 minutes is 900 ml an hour, about 21.6 litres a day. Over a year that is nearly 8 cubic metres of water, before counting hot water energy if it is the hot side.
A cold tap wasting 20 litres a day might cost roughly £30 to £50 a year once water and wastewater charges are considered, depending on your tariff. A hot tap with the same loss could cost more because the boiler or immersion heater is replacing heat all day. A thin constant trickle can easily move into the £150 to £250+ a year range, which is why the cheapest option is often to repair it promptly.
Isolate the Supply and Check the Stop Valves
Before any DIY work, turn off the local isolation valve under the basin or sink if one is fitted. Most modern installations have small slotted valves on the hot and cold flexi pipes, which turn a quarter turn with a flat screwdriver. If there are no local valves, you may need to turn off the main stopcock, usually under the kitchen sink, in a hallway cupboard, or sometimes in a communal area in converted buildings.
Be careful with stiff stopcocks in older London properties. We regularly find stopcocks that have not moved for ten years, painted pipework, seized gate valves, and isolation valves that crumble when touched. If the valve will not turn with reasonable pressure, do not force it. A failed stopcock can turn a dripping tap repair into an urgent leak.
For flats, check whether the stopcock serves only your property. In some mansion blocks and older conversions, supplies can be awkwardly shared or poorly labelled. If you are unsure, call a plumber rather than shutting valves at random and cutting off neighbours.
Strip the Tap Carefully and Identify the Correct Part
Once the water is isolated, open the tap to release pressure. Remove the handle cover, handle screw and headgear or cartridge, keeping parts laid out in order. Traditional taps often need a washer, usually only a few pounds for the part, but a worn tap seat may also need reseating.
Modern mixer taps are less forgiving. Cartridges vary by diameter, spline count, height and whether they are hot, cold or mixer cartridges. A generic cartridge that is nearly right can still drip or make the handle stiff, so take the old cartridge with you if buying parts, or let a plumber match it properly.
In hard-water areas, expect scale around the valve body. Clean the seating surface gently and remove grit before refitting. Do not over-tighten ceramic cartridges because cracking the body of a cheaper tap can mean replacing the whole unit.
Replace the Washer, O-Ring or Ceramic Cartridge Correctly
For a washer tap, fit the correct size washer and check the jumper and retaining nut are sound. If the brass seat inside the tap is pitted, a new washer may still drip, so the seat may need cutting with a tap reseating tool. This is a common reason DIY repairs fail after a day or two.
For a mixer tap, replace the cartridge or O-rings with matching parts and lubricate seals with a suitable silicone grease, not general-purpose oil. Reassemble the handle so the movement is smooth and the hot and cold orientation is correct. Turn the water back on slowly and check both the spout and underside of the tap for at least five minutes.
If the tap is connected to very old pipework, lead pipe, corroded copper, or unsupported flexi hoses, this is where professional help is sensible. Plumbing work in domestic properties should comply with the Water Supply Water Fittings Regulations, and any replacement fittings should be suitable for UK potable water use. We would normally use approved fittings and fit or renew isolation valves where needed so the next repair is easier.
Check for Damage Around the Sink, Bath or Worktop
Do not stop once the drip has gone. Look for swelling, staining, soft timber, lifted laminate, black mould, loose silicone and damp smells inside the unit. In rental properties, photograph the area before and after so there is a clear record of the repair.
A dripping kitchen mixer can cause water to creep under the tap base and into a chipboard worktop. Once chipboard swells, it rarely goes back flat. We have seen small leaks lead to worktop sections needing replacement, which can cost from around £300 to £1,000+ depending on the material, sink cut-outs and access.
In bathrooms, check behind bath panels and pedestal basins. Older panels can hide water damage until the floor covering lifts. If you find soft flooring, damp plasterboard, or a musty smell, get it inspected before simply resealing over the problem.
Decide Whether Repair or Replacement Makes Better Sense
A straightforward washer or cartridge repair during normal hours in London is often around £90 to £180 including labour, with common small parts adding £5 to £35. A like-for-like tap replacement is commonly around £140 to £300 for labour and basic materials, plus the tap itself. Better quality kitchen mixers can push the total to £250 to £450+, especially if new flexi hoses, isolation valves or awkward access are involved.
Repair makes sense when the tap body is solid, parts are available and the finish is still in good condition. Replacement makes more sense if the tap is heavily scaled, the chrome is pitted, the body is loose, the cartridge is obsolete, or the tap has leaked around the base for a long time.
For commercial premises, cafes, offices and rented flats, we usually recommend fitting a decent branded tap rather than the cheapest possible option. Cheaper taps can have poor cartridges, flimsy fixings and non-standard parts, which means the next leak arrives sooner and is harder to repair.
Plan the Repair Around Access, Tenants and Water Use
The best time to fix a dripping tap is during normal working hours before it becomes urgent. Out-of-hours plumbing callouts in London can easily sit around £150 to £300 for attendance and the first part of the visit, before parts or follow-on works. If the tap can be isolated safely, it is usually cheaper to book a planned repair.
For landlords, ask the tenant for a short video showing the drip and a photo under the sink. That helps the plumber bring common cartridges, washers, flexi hoses and isolation valves. It can also show whether there is a bigger leak below, which changes the urgency.
For leasehold flats and communal freehold buildings, check access rules before shutting off shared water supplies. Some blocks require notice to residents or the managing agent. In older Kensington and Chelsea buildings, a simple basin tap job can take longer if stopcocks are hidden behind boxing, under kitchen units, or in locked service cupboards.
If there is water near electrics, such as a leak under a kitchen sink beside a socket spur, dishwasher connection, waste disposal unit or boiler controls, stop using the area and arrange a professional inspection. Water and electricity are not worth guessing with. If any electrical fitting has been wet, it should be checked by a competent electrician before being put back into use.
Practical Timing, Costs and London Property Considerations
- Do not ignore a hot tap drip. You may be paying for water, wastewater and heat. If an immersion heater is involved, the running cost can climb faster than people expect.
- Fit isolation valves if they are missing. Adding or replacing accessible isolation valves during a tap repair may add roughly £25 to £80 in parts and labour, but it makes future repairs quicker and safer.
- Expect limescale in London. Scale can make cartridges stick and aerators block. Cleaning or replacing the aerator can improve flow, but it will not fix a worn internal valve.
- Watch concealed leaks. A dripping spout is visible. A leak from a flexi hose or tap base may only show as swelling in the cabinet or a stain on the ceiling below.
- Choose taps with replaceable parts. For rental and business properties, we prefer fittings where cartridges and hoses are readily available rather than unusual imported designs.
If you want the job handled without trial and error, our plumbing services team can inspect the tap, isolate the supply properly, repair or replace the faulty parts, and check for any hidden water damage at the same visit.
Frequently Asked Questions
Q1: Does a dripping tap really increase my water bill?
Yes, if you are on a water meter. A slow drip may only be tens of pounds a year, but a constant trickle can waste enough water to cost £150 to £250+ annually.
Q2: Is it cheaper to repair a tap or replace it?
Repair is usually cheaper if it only needs a washer, O-ring or common cartridge. Replacement is often better when the tap is badly scaled, loose, corroded, leaking from the body, or fitted with obsolete parts.
Q3: Can I fix a dripping tap myself?
You can try if you can isolate the water safely, identify the correct part and reassemble the tap without forcing anything. Call a plumber if the stopcock is seized, the pipework looks corroded, the leak is below the sink, or you are in a flat with shared services.
Q4: Why does my tap still drip after changing the washer?
The tap seat may be pitted, the washer may be the wrong size, or the tap headgear may be worn. On mixer taps, the wrong cartridge is a common cause of repeat dripping.
Q5: When is a dripping tap urgent?
It is urgent if water is leaking under the sink, reaching electrics, damaging units, dripping through a ceiling, or if you cannot isolate it. A simple spout drip is usually a planned repair, but it should still be fixed promptly.
The plain answer is that a dripping tap can cost you money, and the longer it is left the more likely it is to become a damaged unit, stained basin, wasted hot water or awkward emergency visit. If you would rather have it checked and repaired properly, Kensington Maintenance Services Ltd can send an experienced plumber to diagnose the fault, fit the right parts, and advise honestly if replacement makes better sense. You can get a quote or contact the team and we will help you sort it before a small drip becomes a larger bill.