Toilets and cisterns

Toilet repair in London

A flush button that does nothing. A cistern that hisses and refills through the night. A puddle by the pan that is back every morning however often it is wiped up. Almost every toilet fault comes down to a handful of inexpensive parts in the cistern or at the joints. The checks below are safe to try yourself, and a few faults can be put right on the spot. If they do not sort it, Ninja Plumbers will.

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  • Price agreed before work starts
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What we cover

What this includes

  • Toilets that will not flush, or take several goes
  • Cisterns that keep running or refilling on their own
  • Slow filling and weak flushes
  • Leaks at the base of the pan
  • Leaks between the cistern and the pan
  • Flush valves, fill valves, siphons and buttons replaced
  • Concealed cisterns and wall-hung toilets
Before you call

Worth knowing first

A little of this might mean you do not need to call us at all — we would still rather you knew it.

Lever or button: two different mechanisms

An older toilet with a lever usually flushes with a siphon: the lever lifts a thin plastic diaphragm, and when that splits you end up pumping the handle. A push-button toilet uses a drop valve instead, lifted by a rod or cable from the button. Take the lid off and flush with it open. A link that has come unhooked or a rod that has slipped is often the whole fault, and it clips back in a minute.

A cistern that will not stop running

With the lid off, look at the water level. Up at the top of the overflow means the fill valve is not shutting off — the float may need setting lower, or the valve has worn. Below the overflow but still trickling into the pan means the flush valve seal is letting water past. To check, add a few drops of food colouring to the cistern and leave it half an hour. Colour in the pan means the seal has gone.

Slow to fill, weak to flush

First check the isolation valve on the pipe to the cistern: on most, a screwdriver slot in line with the pipe means open, and one left half-closed makes the cistern crawl. After that, limescale is the usual suspect in London. It furs up the fill valve and its filter, and blocks the flushing holes under the rim. A weak flush can also be a water level set too low.

Water round the base of the pan

Dry everything with kitchen roll and watch where it comes back. Droplets all over the cistern on a cold day are condensation, not a leak. Water only after flushing usually means the pan connector — the sleeve joining the pan to the soil pipe — or the joint under the cistern. Water whether anyone flushes or not points at the supply pipe, the valve, or a hairline crack in the pan. In a flat, a slow leak here ends up on the ceiling downstairs.

Leaking between cistern and pan

On a close-coupled toilet the cistern sits directly on the back of the pan, sealed by a large foam or rubber washer and held by two bolts with washers of their own. When those perish, it drips from under the back with every flush. Tightening the bolts harder is tempting, and it is how pans crack. The proper fix is to drain the cistern, lift it off and renew the washers.

Concealed cisterns and wall-hung toilets

Many newer London flats and refurbished conversions hide the cistern behind a panel, with only a flush plate showing. On most, the plate lifts off and the valves come out through the opening behind it, so nothing needs breaking. Parts vary by frame maker, so a photo of the plate helps. If a cistern has been tiled in with no access at all, we will explain what is needed before touching anything.

When it is not a repair

If the water rises in the pan instead of flushing away, the toilet is blocked rather than broken, and our blocked toilet page covers that. A cracked pan or cistern cannot be repaired properly, and nor can a design nobody makes parts for any more. Replacing the whole toilet is covered on our toilet installation page, and we will be honest about which side of that line yours is on.

Pricing

What affects the price

Most toilet repairs come down to one worn part inside the cistern, and the price reflects that. What changes it is which part has failed, how easily it can be reached and whether a matching part is to hand.

Fill valve, flush valve or seal

A fill valve that will not stop refilling, or a flush valve letting water trickle into the pan, is usually a quick swap. A leaking seal between cistern and pan on a close-coupled toilet means taking the cistern off to renew it.

Concealed cisterns

If the cistern is hidden behind a panel or wall, the repair is done through the flush-plate opening or an access panel. Where there is no proper access, or it has been tiled over, getting to the parts takes longer.

Standard or brand-specific parts

Universal valves fit many cisterns and are easy to carry. Some toilets, especially older designer models and some concealed units, need a part made by the same manufacturer, which may have to be ordered. A photo of the inside of the cistern helps.

The state of the old fittings

On an older toilet, the cistern bolts may be rusted solid, the isolating valve may not turn, and the supply pipe may be corroded. Freeing or replacing those before the new part goes in adds time to an otherwise small job.

The price is agreed before any work starts. We take card and cash.

Questions

Common questions

Is it safe to put my hand in the cistern?

Yes. It is clean supply water that has never been near the pan. Turn the isolation valve off and flush first, so the cistern is empty while you look.

My toilet only flushes if I pump the handle.

That is the classic sign of a split siphon diaphragm. On many close-coupled toilets the cistern has to come off to reach it, and fitting a two-part siphon at the same time makes any future change much easier.

Can I fix a running toilet myself?

Often. Setting the float lower so the water stops below the overflow is simple, and most handy people can swap a fill valve. Changing a flush valve on a close-coupled toilet usually means taking the cistern off, which is where new leaks tend to get made.

Is an old toilet worth repairing?

Nearly always, if the pan and cistern are not cracked. Most parts are standard and fit a wide range of toilets. Replacement makes sense for cracked ceramics, or unusual designs with no parts left.

Can you repair a wall-hung toilet without taking the wall apart?

Usually, yes. Most concealed cisterns are serviced through the opening behind the flush plate. If yours needs more access, we will tell you before anything is opened up.

The water rises when I flush and will not go down.

That is a blockage, not a fault with the flush. Stop flushing, and see our blocked toilet page for what to do next.

Other services

More plumbing work we take on

Need toilet repair in London?

Describe the problem and give us your area, and we’ll tell you the price before anyone starts work.