Toilet Repair & Replacement in North West London

How to tell which part of the toilet is failing

Take the cistern lid off and watch one full flush and refill. Most toilet faults show themselves within a minute. If water keeps trickling into the pan long after the flush, the flush valve is not sealing. On modern push-button cisterns this is the rubber washer at the base of the drop valve, which hardens and picks up limescale. If the water level in the cistern keeps rising until it spills into the overflow, the fill valve is not shutting off.

If the cistern takes ages to fill, the fill valve or its filter is partly blocked, or the isolating valve is only half open. For a leak you cannot see, use the paper test. Wipe the back of the pan dry, lay a sheet of toilet paper across it and leave it overnight without flushing. A wet sheet in the morning means water is getting past the flush valve.

• Constant trickle into the pan: flush valve seal
• Water running into the overflow: fill valve
• Water on the floor after flushing: pan connector or cistern seal
• Pan moves when you sit down: fixings or the floor

Why does a running toilet matter?

A running toilet wastes water every hour of every day, and on a metered supply the tenant or owner pays for it. Waterwise, the water efficiency charity, said when it launched its Leaky Loo Challenge on 22 January 2025 that leaky loos can waste between 200 and 400 litres of water a day. It also matters under the Water Supply (Water Fittings) Regulations 1999. They say no water fitting may be installed or used in a way likely to cause waste or undue consumption of water.

Every flushing cistern must have a warning pipe, or a no less effective device, so an overfilling cistern shows itself. On most modern cisterns that device is an internal overflow into the pan. A fill valve that has stopped shutting off will run into the pan quietly instead of dripping outside, so it is easy to miss.

Water on the floor: pan connector or close-coupled seal?

Water that appears only after a flush is coming from one of two places, and dry tissue tells you which. Press a sheet of toilet paper around the back of the pan where it meets the soil pipe, then flush. If it comes away wet there, the pan connector is leaking. Connectors are rubber or plastic sleeves, and they split or shift when the pan is knocked or the floor moves. If the tissue is dry at the back but water runs down the outside of the pan from under the cistern, the close-coupled seal has failed.

That is the large rubber washer between cistern and pan, plus the washers on the two bolts holding them together. It needs the cistern lifted off and the seals renewed. Tightening the bolts harder is the usual DIY attempt, and it can crack the cistern. If the floor is wet all the time, even between flushes, look at the supply pipe and isolating valve behind the toilet instead.

Why is my toilet wobbling, and is it serious?

A pan that rocks has usually lost its floor or wall fixings, or the floor beneath it has moved. It is worth fixing promptly, because every rock flexes the pan connector until it leaks. On a solid floor, we refix the pan with new screws and suitable packers, then reseal it. On a timber floor, a rocking pan can be the first sign that a slow leak has softened the boards underneath.

We check before refixing. If the boards are soft, they need replacing before the toilet goes back, or the fixings will fail again. Wall-hung toilets that move point to the frame behind the wall, which needs the panel opened.

Repair or replace the toilet?

Repair it if the pan and cistern are sound and parts are available. Fill valves, flush valves and seals are inexpensive, and a repaired toilet works as well as a new one. Replace it if the pan or cistern is cracked, even a hairline crack, because a crack under pressure can split without warning. Replacement also makes sense if parts for an obscure or discontinued cistern are unobtainable, or if the toilet keeps blocking because the pan is poorly designed.

One rule affects old toilets. The Water Fittings Regulations limit a single flush to 6 litres. A cistern installed before 1 July 1999 may be replaced with one delivering a similar volume, but an old single-flush cistern may not be swapped for a dual-flush one under that exception. So a pan designed for a large flush often needs the whole WC replaced, not only the cistern.

Fitting a new toilet: what is involved?

Replacing a toilet is a defined job, so we price it as a fixed price before we start. GOV.UK lists replacing baths, toilets, basins and sinks among the work that does not need building regulations approval. The practical questions are the ones that decide the price. Does the new pan's outlet line up with the existing soil pipe, or does it need an offset connector?

Is there an isolating valve, and is the supply pipe in the right place for the new cistern? Is the floor level and sound? Back-to-wall and wall-hung toilets need a concealed cistern or frame, and access panels for later repairs. We check all of this on photographs or a short visit, then confirm the price.

Toilet faults in rented property

A toilet is one of the sanitary installations a landlord must keep in repair and proper working order, under section 11 of the Landlord and Tenant Act 1985, for most tenancies under seven years. Worn valves, failed seals and cracked pans are the landlord's to repair. Damage the tenant causes, such as a cistern lid dropped and broken, is different. Tenants should report a running or leaking toilet in writing as soon as they notice it.

A slow leak at the base can rot the floor or come through the ceiling below, and a late report makes that worse. In a toilet that is the only one in the property, a fault that stops it being used is treated as an emergency. We attend same day in opening hours, Monday to Saturday, and on Sundays take emergency calls only.

What affects the price of a toilet repair?

Repairs are charged at an hourly rate, so the question is time and parts. A standard fill valve or flush valve seal is quick. A close-coupled seal takes longer, because the cistern has to come off, and old seized bolts can need cutting. Concealed cisterns behind a panel or tiled boxing take more time to reach.

For a new toilet, the price depends on the WC itself, whether the soil connection lines up, the state of the floor, and removal of the old one. A wall-hung toilet with a new frame is a much larger job than a close-coupled swap.

Certificates and defined jobs are a fixed price confirmed before we attend; repairs are charged by the hour, with the rate and an estimate confirmed before we attend.

Toilet repairs across Harrow and nearby

We repair and replace toilets across Harrow, Kenton, Stanmore and Edgware, and in Pinner, Wealdstone, Harrow Weald, Hatch End, Kingsbury, Queensbury, Wembley, Mill Hill and the surrounding areas. Harrow's water is very hard, and limescale is a common reason fill valves stick and flush valve seals stop sealing. Downstairs cloakroom toilets added under the stairs in older houses are often tight to work on and sometimes use a pumped macerator, which we also repair.

Plumbing by area: Plumbers in Harrow, Plumbers in Kenton, Plumbers in Stanmore, Plumbers in Edgware, Plumbers in Bushey, Plumbers in Colindale, Plumbers in Hendon, Plumbers in Mill Hill, Plumbers in Northolt, Plumbers in Northwood, Plumbers in Pinner, Plumbers in Ruislip and Plumbers in Wembley.

What sits outside this job

If a leak has already damaged the floor joists or the ceiling below, we will repair the toilet and replace floorboards where needed, but structural timber repairs are outside what we do. We do not supply designer sanitaryware to order without a specification. If the soil stack itself is cracked or leaking outside, that is a separate repair we will quote. Blocked toilets are covered on their own page.

Why people trust us

• Repairs tested before we leave, and the area left clean
• A walk-in office on Kenton Lane, not a serviced address
• We diagnose first and tell you what we have found before doing more
• A time slot rather than a morning-or-afternoon window
• Work photographed before and after, and reported
• We tell you when you do not need something we sell

We are building a review profile under this name and would rather show you none than borrow someone else's. Ask us for references from landlords and we will put you in touch.

Official sources

• Waterwise: Leaky Loo Challenge launch, 22 January 2025
• legislation.gov.uk: Water Supply (Water Fittings) Regulations 1999, Schedule 2 (para 25, WCs)
• GOV.UK: Building regulations approval, when you do not need approval
• legislation.gov.uk: Landlord and Tenant Act 1985, section 11

Last reviewed October 2026 by EliteShires Property Services.