Repair a tap, toilet, shower or valve when the fault is in a replaceable wearing part, such as a washer, cartridge, fill valve or flush valve, and the body of the fitting is sound. Replace it when the body itself is cracked, corroded or leaking, when parts are no longer made for it, or when the same fitting keeps failing and each repair costs a good share of a new one.

The rule of thumb we use

When we are called to a faulty fitting, we ask four questions:

1. Is the fault in a wearing part or in the body? Washers, O-rings, cartridges, fill valves, flush valves and seals are designed to be replaced. A cracked ceramic pan or a corroded valve body is not.
2. Can we get the part? For common brands, parts are easy. For discontinued ranges, a replacement cartridge may be unobtainable or a poor fit.
3. How often has it failed? One repair in several years is normal wear. The same fitting failing every few months points to a deeper problem, or a fitting at the end of its life.
4. What is the fault costing you? A dripping hot tap wastes heated water. A running toilet can waste a large volume on a metered supply. A leak into a floor or ceiling can cost far more than the fitting.

Most of the time a straightforward plumbing repair is the right answer. Below is how that plays out for each type of fitting.

Taps

Taps fail in predictable ways, and most are repairable.

• Dripping from the spout. On an older tap with a rising spindle, this is usually a worn washer. On a quarter-turn tap, it is usually the ceramic disc cartridge. Both are replaceable.
• Leaking around the handle or spindle. Usually a worn O-ring or gland packing. Repairable.
• Leaking from the base or the tap body. If it is the connection underneath, it can often be remade. If the body is cracked or corroded, the tap needs replacing.
• Stiff or crunchy to turn. Often limescale on the cartridge. Cleaning or replacing the cartridge usually cures it.

Replace the tap when: the body is cracked or pitted, the chrome is failing and corroding, a cartridge for that model cannot be found, or you are changing the basin or sink anyway.

Toilets

A toilet is a simple machine: a fill valve lets water in, a flush valve or siphon lets it out, and a pan carries it away.

• Running into the pan. The flush valve seal or siphon diaphragm is worn, or the fill valve is overfilling into the overflow. Repairable, and our guide on how to fix a running toilet explains how to tell which.
• Weak or incomplete flush. Often a worn siphon diaphragm, a low water level in the cistern, or a partial blockage. Our article on a toilet not flushing correctly walks through the checks.
• Slow to refill or noisy filling. Usually the fill valve. Repairable.
• Leaking between cistern and pan. Usually the doughnut washer or cistern bolts. Repairable.
• Water on the floor at the base. Could be the pan connector, which is repairable, or a cracked pan, which is not.

Replace the toilet when: the pan or cistern is cracked (even a hairline crack in ceramic can open up), the cistern is an obsolete design with no parts available, or the pan keeps blocking because of its shape and every fix is temporary.

Showers

Showers come in several types, and the repair decision depends on which you have.

Shower type	Common repairable faults	Signs it is time to replace
Thermostatic mixer (bar or concealed)	Temperature swings from a scaled or worn cartridge, drips from a worn seal, a blocked filter or head	Leaking valve body, cartridge no longer available, concealed valve leaking inside the wall
Manual mixer	Worn cartridge, stiff controls, scaled head	Body cracked or corroded, no parts
Electric shower	Blocked head, faulty pressure relief device, failed switch or element	Repeated failures, parts not available, cracked casing, water getting inside the unit
Power shower (with pump)	Pump noise, pump seal leaks, scaled head	Pump failing again after repair, whole unit worn

If your shower goes suddenly hot or cold, the cause is often not the shower at all but a pressure change elsewhere in the system. Our guide on a shower running hot and cold explains how we narrow that down.

Electric showers are a combined plumbing and electrical appliance. Anything beyond descaling the head or clearing the filter involves live parts and should be left to a qualified engineer.

Replace the shower when: the valve body is leaking (especially a concealed one, where a leak is inside the wall), parts are discontinued, or you are upgrading because the pressure or flow never suited your hot water system. A new shower installation is also the time to check the valve suits your water pressure.

Valves: isolation valves, stopcocks and radiator valves

Valves spend years doing nothing and then need to work perfectly on the one day there is a leak.

• Isolation valves (the small valves under taps and toilets) often seize or stop sealing. They are inexpensive and quick to replace, and it is rarely worth trying to free a seized one.
• The main stopcock can stiffen or fail to shut off completely. If yours will not close, or it drips from the spindle when turned, get it replaced. You need to be able to turn off your water in an emergency.
• Gate valves on older systems, often on pipes from a loft tank, are known for failing to shut off fully. Replacing them with quarter-turn valves is a common upgrade.
• Radiator valves that weep at the spindle can sometimes be fixed by tightening the gland or changing an O-ring. A leaking valve body means replacement, which usually means draining down at least part of the heating system.

Signs a fitting is finished

Whatever the fitting, these point towards replacement rather than repair:

• Cracks in ceramic, plastic or metal bodies.
• Green or white corrosion that returns after cleaning, or pitting on metal.
• The same fault returning soon after a repair.
• No parts available for the make or model.
• Water damage appearing around a fitting that has already been repaired.
• The fitting does not suit how you now use the room, or the water pressure you now have.

When replacement is the better investment

Sometimes a fitting is repairable, but replacing it makes more sense. A tap that drips from a worn cartridge could be repaired, but if the basin is chipped and the waste is leaking too, doing them together in one visit is often better value. Similarly, if water pressure across the house has changed, for example after a new boiler or a new supply pipe, a new shower valve may perform far better than a repaired old one. If pressure is the real issue, read our guide to low water pressure in the whole house first.

What it costs with Vantage

In normal working hours there is no call-out fee. After the first hour, time is charged in half-hour steps, and parts are quoted before we fit them, so you can choose between repair and replacement with the prices in front of you. Evening, weekend and overnight visits are charged at the out-of-hours rates. Every rate is published on our prices page, so you know what you will pay before we arrive. Our vans are fully stocked with common washers, cartridges, valves and toilet parts, so many repairs are done on the first visit.

Frequently asked questions

Is it worth repairing an old tap?

Usually yes, if the body is sound and parts are available. A new washer or cartridge is a small job. If the tap is corroded, cracked or an obscure model with no parts, replacement makes more sense.

How do I know if my toilet pan is cracked?

Look for a fine line in the ceramic, often near the base or the back, and water appearing on the floor even when the pan connector is dry. Hairline cracks can be hard to see, so a plumber will dry the area and check each joint in turn.

Why does my new tap cartridge keep failing?

Hard water is a common cause, because limescale wears the ceramic discs and seals. Debris in the pipework after work on the water supply can also damage a new cartridge. If it keeps happening, the plumber should check for grit and consider a filter or scale treatment.

Should I replace all my isolation valves at once?

Not necessarily, but it is worth testing them all once a year. Any that are seized, weeping or fail to stop the flow should be replaced. It is often convenient to do them together while the water is off.

Can a leaking shower valve be repaired?

If the leak is from a worn cartridge or seal, yes. If the valve body itself is leaking, particularly on a concealed valve inside the wall, it needs replacing, and that can mean opening up the wall or tiling.

Plumbing repairs across Hertfordshire, Bedfordshire and Cambridgeshire

Our own engineers repair and replace taps, toilets, showers and valves from our base in Stevenage across Hertfordshire, Bedfordshire and Cambridgeshire, with a 12 month labour guarantee on our work. Find out more about our general plumbing repairs or call 01462 506374. The phone is answered 24 hours a day, 7 days a week.