Taps and toilets
85 min
Two hosts talk the lesson through. The voices are synthetic; the script was written from this lesson and checked against it, and asserts nothing the lesson does not.
- Diagnose a dripping tap as a washer tap or a ceramic-disc tap, and state the fix, its source and the kind of fitting it was written for, including where this course found no method
- Apply the isolate-and-check step before opening a tap, and decide what to do when the check fails
- Diagnose a running toilet in a UK or a US home from the dye test and the overflow pipe, and decide whether the fix is yours or a plumber's
Dripping taps and worn toilet flappers are among the common household leaks that the US Environmental Protection Agency (EPA) names,3 and both are easy to get wrong in one particular way: by buying a part before you know what's inside. A washer from the hardware shop does nothing for a tap that has no washer in it, and a part made for an American toilet is a guess in a British one. Lesson 2 taught you to prove a leak and find it. This lesson fixes the ones a householder can fix, and it names, for every method, the source and the kind of fitting it was written for, because the method that suits one tap can do nothing for the next.
This course is education, not a trade qualification, and not legal advice about your own home. It teaches no gas work and no wiring. If you smell gas in Great Britain, open doors and windows, turn the gas off at the meter if you can do it safely (not if the meter is in a cellar or basement), and call 0800 111 999; in Northern Ireland the number is 0800 002 001. In the US, leave straight away and call 911 or your gas utility once you're outside. In either country, don't light a flame or touch an electrical switch. Isolate the water or power before you open anything up, and if a breaker, RCD or GFCI keeps tripping, leave it off and call an electrician. Which jobs the law leaves to a registered or licensed trade differs between England, Wales, Scotland, Northern Ireland and each US state, and it changes.
Most repairs here open something, so the callout's "isolate the water" is the first step of each. It means the stop tap (stopcock) in a UK home or the main shut-off valve in a US one, from lesson 1, How a house works, and where it switches off, or a small isolation valve on the pipe to one tap, where the installer fitted one. Isolating is half the step. The other half is checking that it worked, and one of the sources below has a step that lets you check it.
Two kinds of tap
This course read a method for each of two kinds of tap, and the two fail differently. That is the whole reason to diagnose before you buy anything.
A washer tap has a washer inside it, and washers wear. Southern Water, an English water company, says that while a dripping tap can have a few causes, most of the time the washer has become degraded over time, and replacing it can be a simple fix.1 EPA's WaterSense programme says the same of American faucets (the US word for taps): "Old and worn faucet washers and gaskets frequently cause leaks in faucets."3 Neither source describes how a washer seals or exactly what wears, so this course does not either.
A ceramic-disc tap has a cartridge instead. Bristan, a UK tap maker, says that for one of its own single-lever sink taps a drip for a short time after use is normal, from water left in the tap body, and that a drip that continues is possibly due to what it calls the ceramic disc valves or cartridge.2 Its leaflet's maintenance panel shows cleaning the cartridge, not changing a washer.2
How do you tell which you have? This course read no source that gives a test from the outside of a tap. Two things do tell you. The first is the paperwork: if you have the maker's leaflet, or the maker's name is on the tap, the maker says what is inside. The second is what you find inside, with the water isolated. Here is this course's own reading of the two sources: if the tap top comes out and under it you find a small plate, which Southern Water calls the jumper plate, and a washer, it's a washer tap; if you find a cartridge under the shroud (the cover over the cartridge), as Bristan shows, it's a ceramic one.12 A nut on its own does not tell you, because Bristan's tap has one too. Getting inside is a method in itself, and the only one this course read that doesn't need the maker's leaflet is Southern Water's, for a tap whose cover unscrews to show a hexagonal nut. A tap that doesn't open that way, such as a lever held on by a small screw in its handle, stays shut until you have its maker's instructions. That rule is this course's.
Before you read the method: a washer tap drips, and you've just fitted a new washer and put it back together. What's the one mistake in the reassembly that the source warns can undo the repair?
Show the answer
Screwing it back together too tightly. Southern Water says to be careful not to, because you may damage the new washer.1 The instinct after a drip is to tighten everything, and here it works against you.
A washer tap, step by step
This is Southern Water's method, written by an English water company for a UK washer tap: the kind with a cover, a hexagonal nut, a jumper plate and a washer.1 It is Yours, on Southern Water's advice, if it's your home to repair or your landlord agrees.
- Turn off the water at your stop tap. Southern Water says to do this always, before taking the tap apart, to avoid a potential mess.
- Turn the dripping tap on full. A few drops may come out before it stops completely.
- Unscrew the tap's cover to reveal the hexagonal nut. Loosen the nut with a spanner (wrench) and lift out the whole tap top. Lay the parts out in the order you took them off, so they go back together the same way.
- Lift out the jumper plate, unscrew the nut with pliers (Southern Water's tool), and replace the old washer with a new one.
- Put the tap back together, not too tightly, because you may damage the new washer. Turn the water back on at the stop tap. The drip should have stopped.
- If it hasn't, Southern Water says to hire a plumber "qualified to meet the regulations for working safely with drinking water".1
Step 2 is easy to skip. Southern Water gives it without a reason, and this course uses it as your check: if the tap does not stop running after you've turned the stop tap off, the water to that tap is not off, and you do not open it. That rule is this course's. WaterSafe does say a stop tap may take a few minutes to stop the water altogether, so give it that.5 Southern Water does not say why a tap might keep running beyond that, and this course will not guess. The Energy Saving Trust says a regular boiler has two extra header tanks to store cold water, usually installed in the loft (attic),6 but no source read here says whether those tanks feed a tap that the stop tap doesn't control. Lesson 7, Heating: boilers, radiators and furnaces, covers how those systems are laid out. Until you know how your hot water reaches the tap, a hot tap that won't stop is a reason to stop there and ask a plumber.
A friend in Devon has a pair of old separate taps on a bathroom basin. The hot one drips. She turns off the stop tap under the kitchen sink, turns the hot tap on full, and ten minutes later it's still running as hard as ever. What should she do, on this lesson's reading?
Show the answer
Stop. Southern Water's second step, as this course uses it, shows whether the water is off, and here it shows it is not. Ten minutes at full flow is past the few minutes WaterSafe says a stop tap may take.5 She should not unscrew anything.
She should turn the hot tap off, then put the stop tap back on slowly, since WaterSafe says to turn a stop tap on and off slowly and never force it.5 Then she can either find out how the hot water in that house is supplied (lesson 7) or call a plumber. Opening a tap that still has water behind it is the mess Southern Water's first step is there to prevent.
A ceramic-disc tap
Bristan's leaflet is for one of its own single-lever sink taps. It is laid out in picture panels, so this lesson paraphrases it rather than quoting it. Its maintenance panel shows, for that tap: turn off the isolation valve on the flexible pipe that feeds it, undo the small grub screw that holds the handle (the leaflet shows a hex key) and take the handle off, take off the shroud and the retaining nut, and lift out the cartridge. Then soak the cartridge in a solution until the scale is gone (the leaflet does not name one), put it back with the nut and shroud, refit the handle, and turn the water on and let it run for a few minutes.2 The leaflet doesn't show fitting a new cartridge. For spare parts it sends you to Bristan's website to search for your product.2 The same leaflet tells the installer to fit isolation valves on the tap's supply pipes, so that it can be maintained later.2
That is one maker's method for one maker's tap. For any other ceramic-disc tap, the job is Yours, on conditions: that you have the maker's instructions for that tap, and any part they name. Without the instructions, it is a job for a plumber.
American faucets, and showerheads
EPA gives no step-by-step for a faucet. It says many tutorials exist online for a wide variety of faucets, and adds one tip: "Don't forget to turn off the water line before you start!"3 This course read none of the tutorials EPA links to, so it has no US faucet method to give. For a US faucet the job is Yours, on conditions: the maker's instructions for your model.
A leaking showerhead is simpler. EPA says some can be fixed by making sure the showerhead is tightly connected to the pipe stem and using pipe tape to secure it.3 That is Yours, on EPA's advice. A shower that drips when it isn't in use is different: EPA calls that a valve leak and sends it to an experienced handyperson or a licensed plumber, so it is Call someone.3
The running toilet
Here the two countries' advice differs, and this course read nothing that says one country's part fits the other's toilet. EPA wrote lesson 2's dye test for American toilets.3 Using it on a UK cistern is this course's own step, as lesson 2 said: the test only asks whether water gets from the cistern into the bowl without a flush. What comes next depends on the toilet.
In a US toilet, the part EPA names is the flapper, a simple rubber valve seal that holds water in the tank and lets it into the bowl when you flush. EPA says the flapper "should be checked periodically and replaced at least every five years".3 A worn one can make the toilet flush on its own or leak silently. EPA calls replacing it a quick fix. Its tip is to take the old flapper, or a picture of it, to the shop so that the new one fits, and to check the width and whether it has a foam float. The owner's manual, if you have it, or the maker's website has information on replacement parts.3 EPA gives no step-by-step on the page, and this course read none. It is Yours, on conditions: the flapper made for your toilet, the water isolated first, which is this course's rule from the callout, and your home to repair or your landlord's agreement. EPA adds that a hardware store or a licensed plumber can help if you need it.3
In a UK toilet, United Utilities names "modern push button toilet cisterns" among the biggest causes of leaks in homes and businesses, and says "Nearly 80% of all leaks reported to us last year were leaky loos!" (the page does not say which year).4 On an older cistern, the sign to look for is the overflow pipe that goes through the outside wall. If it drips, United Utilities says the cistern is faulty and needs repairing.4 This course read no source on the parts of a UK cistern or how they fail, so it gives no parts diagram and no method. Prove the leak with the overflow check and, as this course's own step, the dye test, then follow the cistern maker's instructions if you have them, or use a WaterSafe approved plumber, which is where United Utilities sends its customers.4 With the maker's instructions, it's Yours, on conditions; without them, Call someone.
United Utilities also tells metered customers that if they repair a leak within six weeks they may be able to claim for the water lost.4 That is its own scheme for its own customers. This course did not read other companies' allowances, so ask yours.
A reader in Gwynedd has been reading a US website about toilets. Her push-button cistern leaks into the bowl on the dye test, and she's about to buy a flapper. What would you tell her?
Show the answer
That the flapper advice is EPA's, written for American toilets whose part is a flapper, and a UK push-button cistern is the design United Utilities singles out. This course read no source on what's inside it, so it cannot say which part has failed, and a flapper is a guess. The dye test, used on a UK cistern as this course's own step, has done its job: she knows it leaks. The next step is the cistern maker's instructions, or a WaterSafe approved plumber.
A kitchen tap in a Victorian terrace
This is the simpler of the lesson's two worked cases.
In a Victorian terrace in West Yorkshire, the cold tap on the kitchen sink drips about once a second. It is an old pillar tap (the upright kind with its own handle), one of a separate pair. EPA puts one drip a second at more than 3,000 US gallons a year, which lesson 2 converted to over 11,000 litres.3
Which kind of tap? There is no leaflet, and the maker's name has worn off. So the owner isolates it first, then looks. She turns off the stop tap under the sink, turns the cold tap on full, and waits: a few drops, then nothing, so the check passes.1 She unscrews the cover and finds a hexagonal nut. That alone does not settle it, so she loosens the nut with a spanner, lifts out the tap top, lays the parts out in order, and finds a jumper plate and a washer. That is Southern Water's kind of tap, a washer tap.1
The fix. She follows the rest of Southern Water's steps: jumper plate lifted, nut undone with pliers, washer replaced, tap reassembled without overtightening.1 She closes the tap, and the stop tap goes back on, slowly.5
The check. The drip has stopped. Had it not, Southern Water's advice would be a plumber qualified for drinking-water work.1
A bathroom with two faults
This is the harder case, and it stops partway for you.
A couple buy a 1960s semi in Essex. The basin and its single-lever mixer tap are newer than the house, but the toilet is an older one, with an overflow pipe through the outside wall. The basin tap drips, and outside, the overflow drips onto the path. In a kitchen drawer they find a maker's leaflet for the basin tap.
The tap. The leaflet says the tap has a ceramic disc cartridge, and under the basin there are two small isolation valves on the flexible pipes that feed it.
Before reading on: do Southern Water's washer steps apply to this tap? If not, what does, and what label does the job get?
Show the answer
No. Southern Water's steps are for a washer tap, with a hexagonal nut, a jumper plate and a washer, and the leaflet says this one has a cartridge.1 The method is the one in the couple's own leaflet, for this tap. Bristan's leaflet shows what such a method looks like for one of its taps (isolate, handle off, shroud off, cartridge out and cleaned), but it isn't this tap's.2
Before opening it, they turn the tap on to check the isolation valves have worked, which is this course's step borrowed from Southern Water's. With the maker's instructions it's Yours, on conditions: they follow those instructions and use any part they name. Without the leaflet, it would be a plumber's job.
The toilet. United Utilities gives a dripping overflow as the sign of a faulty cistern on an older toilet, and this one fits that description.4 The couple do the dye test anyway, as this course's own step, to see whether the cistern is also leaking into the bowl, and the bowl stays clear. So the cistern is losing water out of the overflow, not into the bowl. Neither fact tells them which part inside has failed, because this course read nothing on the parts of a UK cistern. There is no leaflet for the cistern. So it is Call someone: a WaterSafe approved plumber.4
What the case teaches is the order. Name the fitting before you buy anything, use the method written for that fitting, and where no method was written for it, don't borrow one.
What people get wrong
"If it drips, turn it off harder." Neither source read here suggests forcing a tap shut. Their fix is a new washer in a washer tap and a cleaned cartridge in Bristan's ceramic one.12 Force comes up in the sources only as a warning: Southern Water's, against screwing a repaired tap back together too tightly, and WaterSafe's, against forcing a stop tap.15
"A drip means a new washer." Only in a washer tap. Bristan's leaflet for its ceramic tap does not mention a washer. It puts a continuing drip possibly down to the ceramic disc valves or cartridge, and its fix is to clean the cartridge.2
"A ceramic tap that drips once after use is broken." Not on Bristan's account. For its own tap, it says a drip for a short time after use is normal, from water left in the tap body. It's a drip that goes on that it puts, possibly, down to the cartridge.2
"Toilet advice is toilet advice." The flapper is the part EPA names in American toilets. United Utilities names modern push-button cisterns among the biggest causes of leaks in the UK.34 This course read nothing on how a UK cistern works, and buying a US part for one is a guess.
"The stop tap's off, so the tap is safe to open." Only once the tap has stopped running. Southern Water's second step, read as a check, is how you find out.1
"A dripping shower head just needs tape." Only if it leaks at the joint. EPA sends a shower that drips when it's off, a valve leak, to a handyperson or plumber.3
Practice
Take 15 minutes over this. It opens nothing, so it suits a renter too.
List every tap in your home. Next to each, write what you know about its kind: the maker's name if it is on the tap, whether you have a leaflet for it, and "unknown" if you don't. Don't take any tap apart for this exercise. If you later do, isolate it first and run the check, and only if it's your home to repair or your landlord agrees.
Look under each basin and sink for small isolation valves on the pipes feeding the taps, and note which taps have them.
For each toilet, note whether it is a US toilet with a tank or a UK cistern, and, in a UK home, find where its overflow pipe comes out through the wall, if it has one, and whether it drips.
Take 10 minutes over this. For each fault, write the kind of fitting, the source whose method or advice applies (or "none read"), and the label: Yours, Yours on conditions (name the condition), or Call someone.
- A pair of old pillar taps in a UK bathroom; the cold one drips, and there's no leaflet.
- A US kitchen faucet with a single handle that drips; no manual.
- A UK push-button cistern that shows colour in the bowl on the dye test; no leaflet.
- A US toilet that seems to flush on its own every hour, with the owner's manual in a drawer.
Compare your four answers with these.
Show the answer
You can't tell from outside. Isolate it, run the check, and look. If the tap top lifts out and you find a jumper plate and a washer, it is Southern Water's method and Yours. If you find a cartridge, there's no leaflet, so it's a plumber's job.
A US faucet. EPA gives no method, and this course read none. With no manual, it is Call someone; with the maker's instructions it would be Yours, on conditions.
A UK cistern, which this course read no method for. No leaflet, so Call someone: a WaterSafe approved plumber, as United Utilities advises.
A US toilet, and a toilet that flushes on its own is one of the things EPA says a worn flapper can cause. Do the dye test to confirm the leak. Then it is Yours, on conditions: the flapper made for that toilet, using the manual's information on parts, with the water isolated first.
For your plan
This lesson adds a line to your map: which taps are washer taps, which are ceramic and whose they are, and where the isolation valves sit. It adds a line to your calendar: in a US home, the flapper checked periodically and replaced at least every five years (EPA); in a UK home, a look at each overflow pipe when you check the stop tap. And it adds a drawer for the leaflets, because the leaflet decides which label a job gets.
Connections
Lesson 1, How a house works, and where it switches off, gave you the stop tap and the three job labels. Lesson 2, Water in: supply, leaks and frozen pipes, gave you the meter test, the dye test and the arithmetic that says a drip matters. Lesson 4, Water out: traps, vents and blocked drains, goes to the other side of the plughole. Lesson 7, Heating: boilers, radiators and furnaces, explains the kinds of system, including the regular boiler's loft tanks, and lesson 8, Hot water: scalds, legionella and the tank, asks how hot the water from the hot side should be.
Go deeper
- Southern Water, "How to fix a dripping tap". Free; read here in full from an Internet Archive capture, because the live page refused automated readers. Six short steps with photos, for a UK washer tap.
- EPA WaterSense, "Fix a Leak Week". Free, read here in full. The flapper, faucet and showerhead advice for American homes, with EPA's tip on matching a flapper.
- United Utilities, "Find leaks inside your home or business". Free, read here in full. The UK toilet signs, and where one water company sends its customers.
- Your own taps' and toilets' leaflets. The course means it. For a ceramic tap or a UK cistern, the maker's instructions are the only method this course can point you to.
Sources
- Southern Water, "How to fix a dripping tap". Read: full text, from the Internet Archive capture 20260515022127, because the live page refused automated readers (it did again on 25 September 2026). The washer-tap method and the plumber advice.
- Bristan, Installation Instructions & User Guide for one of its single-lever sink taps, product code K SNKSL EF C (D2), product file 576945. Read: the whole leaflet as extracted text, and its second page again as the rendered page on 25 September 2026; paraphrased here, not quoted. The maintenance panel, the troubleshooting table, the note on isolation valves and the spare-parts panel.
- US EPA WaterSense, "Fix a Leak Week", last updated 13 March 2026 . Read: full text; re-read on the live page on 25 September 2026. The common leaks, the faucet washers and tip, the showerhead and valve leaks, the dye test, the flapper and the tip on matching it.
- United Utilities, "Find leaks inside your home or business". Read: full text; re-read on the live page on 25 September 2026. The push-button cisterns, the overflow pipe, WaterSafe plumbers and the leakage allowance, all for its own customers.
- WaterSafe, "How can I locate my internal stop tap to turn off my water in an emergency?". Read: full text; re-read on the live page on 25 September 2026. The few minutes a stop tap may take, and turning it on and off slowly, never forcing it.
- Energy Saving Trust, "Boilers" . Read: full text, from the Internet Archive capture 20260919232017, because the live site refused automated readers. Cited only for the header tanks of a regular boiler, which store cold water.
Check your understanding
This lesson has a 5-question quiz. Pass it and the questions come back on a schedule in Review, so what you learned stays learned. Your progress is saved in your browser; no account needed.