A shower head that sprays sideways, dribbles from half its holes or looks crusty round the rim is usually clogged with limescale, the chalky calcium carbonate left behind when hard water dries. Most of the UK has some degree of hard water, so the problem is common, and the cure is a mild acid soak. What turns a ten-minute job into a costly one is not the limescale. It is the wrong product on the wrong finish, a shower unit that was not isolated, or two cleaners that should never meet.
So this guide goes safety first. It covers what to check before you start, the gentlest effective method, what to do if that does not work, and the points at which you should put the spanner down. It sits alongside our deep clean of the whole bathroom and our guide to cleaning shower glass, which deals with the same hard-water marks on the other side of the enclosure.
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Check these before you touch the shower head
Is it an electric shower?
Electric showers heat the water inside the unit, so the head is attached to something wired to the mains. Switch the shower off at its pull-cord or isolator switch before cleaning anything, and keep wet hands, cloths and cleaning liquid away from the unit’s casing and controls. Do not put a plastic bag of liquid over a head that is fixed directly to the unit unless the manufacturer’s manual describes it. Many electric showers have a removable head or a hose and riser rail, and the manual will show how to take it off. Anything that involves opening the unit, replacing the heating element or a tripping fuse is a job for a qualified electrician, not a cleaning task. Mains-fed mixer showers and handheld showers on a thermostatic valve are not live, but still check the manual. If the shower trips the circuit breaker, crackles, smells hot or leaks inside the casing, stop using it and call a qualified electrician. Do not try to descale the heating element yourself, because that means opening a mains-powered unit.
Read the label on the finish
Plain chrome plating and plain plastic cope with a mild acid soak better than most finishes. Brass, brushed nickel, matt black, gold and coloured coatings can be affected by acid, so contact time matters. Coatings that are lacquered or applied by PVD (physical vapour deposition) can dull or stain if you leave acid on them. If the manufacturer says no acid cleaners, believe them, and use warm water and a soft cloth with a tiny amount of mild washing-up liquid instead. The table below shows how to adapt the soak, and it is deliberately cautious.
| Finish | Vinegar or citric acid soak | What to watch |
|---|---|---|
| Plain chrome-plated metal | Normally fine, start with 30 minutes | Rinse well, dry, polish with a soft cloth |
| Plastic or plastic-faced head | Normally fine, start with 30 minutes | Use cool or warm solution, not hot, as heat can warp plastic |
| Brass, copper, nickel or bronze effect | Short contact only, around 15 to 20 minutes, and test first | Acid can dull or darken the metal, so check often |
| Matt black, gold, coloured or PVD coatings | Avoid unless the maker says otherwise | Wipe with a damp cloth, use a toothbrush on nozzles, ask the maker |
| Silicone nozzles | Fine in short soaks | They are designed to be rubbed clear with a finger |
Never mix descalers
Vinegar, citric acid and shop-bought descalers are all acids. Never combine an acid with bleach or any chlorine product, because it can release toxic chlorine gas. That is the main reason to rinse a head thoroughly between products and to use only one at a time, as our guide to cleaning products you should never mix explains. Read the label on shop-bought limescale removers: some contain stronger acids, and some are not suitable for plated or coloured finishes. Open a window, wear rubber gloves, and consider eye protection when working overhead, because a splash of acid in the eye is a real hazard.
Mind the scald risk and the drain
Turn the water off, or to cold, and let the pipework cool before you start. Put a towel or a plug in the shower tray or bath so that small parts such as washers and filters cannot drop down the drain, and so that the tray is not scratched if a spanner slips. A chilly or hot flush at the end of cleaning should be run away from your body.
Protect what is underneath
Vinegar, citric acid and limescale sprays can etch natural stone such as marble, limestone and travertine, and can dull some grout and coloured enamel. If your shower tray or wall is made of any of those, lay a towel over it before you start, wipe up drips straight away with a damp cloth, and rinse the surface with clean water afterwards. Acid also marks some sealants and chrome-plated taps if it dribbles down and dries, so keep a damp cloth to hand.
Is it limescale, and is it worth doing now?
Check the symptoms before you reach for acid, because a few other faults look similar. Limescale on a shower head shows up in a handful of ways.
A weaker or uneven spray
Scale narrows the channels inside the head and in the filter screen, so less water gets through. Pressure then seems to drop gradually, which makes it easy to miss until you notice that rinsing shampoo takes longer. If the pressure is poor at other taps as well, the head is not the cause, and the answer lies with the supply or the plumbing.
Streams that squirt sideways or skip holes
When individual nozzles clog, the others take the flow and the water leaves at odd angles, hitting the wall, the glass or the floor. Hold the head up to the light and look: blocked holes show as white plugs, and clear ones show daylight. The wayward spray also leaves splash marks on screens and tiles, and our guide to shower glass covers those. More upkeep ideas sit under other household topics.
Crust, white rim and rough face
A chalky white or grey crust on the face and round the edges is calcium carbonate left as drops evaporate. It is harmless in itself, but a head in that state is usually blocked behind the face as well.
Slime, smell or pink and black spots
Scale is not the only thing that collects. Soap film and biofilm, the thin slimy layer that bacteria form in damp places, can build up in the head and on the hose, particularly on handheld showers that are damp most of the time. Acid does not clear all of it. A brush, a wash in warm soapy water and, if the hose is old or very grubby, a replacement will do more than a stronger descaler. If the smell is musty or you see black spots on seals, treat it as mould and follow the guidance in our bathroom deep-clean article.
Here is how the usual descaling routes compare, so you can pick the lightest one that suits your head.
| Method | How it works | Best for | Watch out for |
|---|---|---|---|
| White vinegar soak in a bag | Dilute acid dissolves scale over 30 to 60 minutes | Routine limescale on chrome or plastic | Smell, and long contact on metal finishes |
| Citric acid solution | A couple of tablespoons in warm water, soaked for a similar time | Households that dislike the vinegar smell, hard water | Rinse well, as dried crystals can leave a film |
| Detach and soak | Removes the head so the filter and restrictor can be cleaned | Heads with filters, or heavy scale | Do not force a stuck fitting or lose washers |
| Limescale spray or gel | A stronger ready-made acid for short contact | Fixed heads and awkward corners | Check it is safe for your finish and ventilate |
| Toothbrush and toothpick only | Mechanical cleaning of the nozzles | Light build-up, coated finishes | Use wood or plastic, not metal pins |
A short tools list saves a trip up and down the stairs: a freezer bag, cable ties or strong bands, an old soft toothbrush, wooden toothpicks, a microfibre cloth, rubber gloves, a towel for the tray and, only if you will remove the head, an adjustable spanner and a cloth to protect the finish. For a general picture of how the bathroom fits together, see our bathroom deep-clean guide and the cleaning products section, and the Cleaners Guide homepage for other household jobs.
The gentle method: soak it in place
For a standard fixed head on a mains-fed shower, soaking in a mild acid solution is the least risky way to dissolve limescale, since it needs no tools and no unscrewing. Plain white vinegar is the common choice, and food-grade citric acid dissolved in warm water works in a similar way without the smell. Malt vinegar is not suitable because it is brown and can stain.
- Check the finish and decide how long to soak. For plain chrome or plastic, 30 to 60 minutes is a sensible first go, and many guides suggest longer only for heavy scale and where the maker allows it. Metal and coated finishes need less.
- Fill a sturdy freezer bag or food bag with enough solution to cover the nozzles. White vinegar on its own is fine, and white vinegar from a supermarket or online works as well as any. For a smell-free alternative, dissolve a couple of tablespoons of food-grade citric acid powder in about a litre of warm water. Warm, not hot, especially for plastic.
- Lift the bag so the head is fully submerged, and secure it to the shower arm with a cable tie, hair tie or strong elastic band. Double-bag it if you are leaving it, so a split does not tip acid over the bath.
- Leave it for the time you chose, checking occasionally to see whether the finish is changing in any way. If it starts to dull, stop and rinse.
- Remove the bag over the bath or tray and tip the used liquid away. Run the water for a minute or two, pointing the head away from you.
- Rub the nozzles with an old toothbrush or, if you have a silicone-nozzle head, with your thumb. Rinse, dry and polish with a soft cloth.
Check the spray. If every nozzle runs evenly and the pressure has improved, you are done. If some holes remain blocked, it may be worth a second, longer soak, but not an overnight one on metal finishes, because the longer acid sits on metal, the more chance of pitting or dulling.
If the bag keeps slipping
Bags tend to sag and tip as the weight of the liquid pulls them down. Fix them tightly at the arm, support the bottom with a stack of towels on a stool or a bucket under it, or use a bowl of solution instead and lower a detached head into it. Press out trapped air bubbles, since air pockets stop the solution reaching some nozzles.
Taking the head off for a proper clean
If soaking in place leaves holes blocked, or the head has a filter or flow restrictor you want to clear, remove it. It is also easier to rinse properly.
- Turn off the water and, for an electric shower, isolate the power. Put a towel in the tray.
- Wrap a cloth round the connection to protect the finish. Hold the pipe or arm steady with one hand, and turn the head anticlockwise. Hand tight should come undone with a gentle turn. If it has seized, use an adjustable spanner on the cloth and do not force it. A stuck fitting that needs a lot of force can crack a plumbing joint hidden behind the wall, and it is better to stop and ask a plumber than to risk a leak inside it.
- Take a photo before pulling anything apart. Remove the rubber washer, any filter mesh and the flow restrictor if it comes out easily. Keep the washers, since they are small and easy to lose.
- Soak the parts in a bowl of vinegar and water, or a citric acid solution, using the contact times in the table above. Do not soak rubber seals for hours, as long exposure may harden them over time.
- Brush the face with a soft toothbrush. For stubborn holes, a wooden toothpick or a plastic pin is safer than metal, which can scratch or enlarge the nozzle.
- Rinse everything thoroughly in clean water and let it dry. Refit the washers, the filter and the restrictor in the same order, screw the head back on by hand and nip it up gently, since overtightening can crush a washer.
- Turn the water back on slowly and check for drips at the joint. If it leaks, retighten slightly or replace the washer. Wrapping a few turns of PTFE tape clockwise round the thread can help with a weeping joint on a metal thread, but if the leak persists, call a plumber.
If you are not sure what a particular part is, leave it in. Many modern heads are sealed units that are not designed to be opened, and prising apart a moulded face plate usually breaks it.
When vinegar is not enough
Thick, old scale, or a head fitted in a very hard water area, may not shift with a household soak. A shop-bought limescale remover is the next step, but treat it with more care than vinegar because the strength and acid type varies by product. Limescale remover sprays and gels are meant for a short contact time on a fixed fitting, but check the label for chrome, plastic and coated finishes before you use one. Never use drain cleaners, toilet cleaners or anything containing hydrochloric acid or bleach on a shower head, and do not use one product on top of another. Rinse the fitting very well afterwards, running the shower for a few minutes with the head pointing away from you.
Different minerals leave different marks. White chalky scale is calcium carbonate and responds to acids. Orange or brown staining can be iron or rust from old pipes, and may need a product made for rust stains, and persistent brown water from the tap is a reason to speak to your water company or a plumber. A greenish tinge on brass can be corrosion, and that is a cue to look at the fitting, not to scrub harder.
If after two or three attempts the spray is still weak, the cause may not be the head at all. Try the water pressure on a different outlet, check that the isolating valves on the pipes feeding the shower are fully open, and consider whether a filter inside the mixer or valve is blocked. Those are jobs for a plumber or, for an electric shower, a qualified electrician.
Rainfall, handheld and multi-function heads
Large rainfall heads have a lot more nozzles, and often a flat face where scale and soap film collect. They are easier to clean by lowering the whole face into a shallow tray or washing-up bowl of solution than by bagging, if you can unscrew them. Check the weight first, because a rainfall head full of liquid is heavy and can wrench a ceiling-mounted arm.
Handheld heads are the simplest. Unscrew them from the hose, soak the head in a jug or bowl, and wipe the hose and the holder, where scale also collects. Check the small cone washer at the hose end and replace it if it has gone hard or flat.
Multi-function heads have a dial or switch that sends water to different groups of nozzles. Cycle through the settings during and after the soak so that all channels get cleaned, and operate the dial gently, since the mechanism is delicate. If a setting stays dead, a deposit may be stuck in the diverter, and this is where a second soak helps most.
Heads with soft silicone or rubber nozzles are made to shed limescale, and rubbing them with a thumb often clears them without any acid at all. If you are fitting a new one in a hard water area, these are worth looking for.
Hard water, cleaning intervals and what actually helps
How often you need to do this depends on the hardness of the water, how much you use the shower and what the head is made of. In soft water areas you may go many months. In hard water areas, scale can show within weeks. There is no useful universal schedule, so use the symptoms as your guide: a weaker spray, a split stream, white crust on the face or a head that sprays on to the wall are all prompts. Many water companies publish hardness by postcode, which gives a good sense of what you are dealing with and whether a softener or a different fitting is worth considering. Anything that softens or conditions water at the supply is a plumbing job.
Why does scale form in the first place? Hard water carries dissolved calcium and magnesium. When the water is heated, or when drops dry on a surface, some of those minerals come out of solution as a hard white deposit. That is why shower heads, kettles and taps all furr up in the same way, and why the nozzle holes, where small drops dry slowly after each shower, are the first places to block. It also explains why a quick wipe of the face after use slows the process: fewer drops dry on the metal.
Daily and weekly habits
- After showering, wipe the face of the head with a cloth to remove drops before they dry into marks. It is quick and it works.
- Run the water briefly before use, if the shower has not been used for a while, pointing the head away from you. Public health guidance on water systems advises flushing outlets that have sat unused, because stagnant water in a shower hose or head is a risk for bacterial growth. If someone in the household is unwell or has a weakened immune system, ask a health professional for advice.
- Replace a handheld hose and head that has gone slimy, cracked or grubby inside, because there is only so much a clean can do for an old, porous hose.
- Keep a squeegee or cloth for the glass or screen, and see our guide on cleaning shower glass for the hard-water marks that go with a limey head.
Is a softener or a different head worth it?
Salt-based water softeners reduce scale through the whole house, but they cost money and need maintenance and the salt, and installing one is plumbing work. Cartridge filters that fit in the shower arm or head claim to reduce chlorine or scale, but their effect on limescale varies, so read what the maker actually says before buying. For most households, an occasional soak and a head with silicone nozzles is the cheaper answer.
Knowing when to replace it
A head is cheap compared with a plumber, and some are not worth saving. Replace it if the face plate is cracked, the finish is flaking or pitted, the threads are damaged, the water leaks from the body rather than the nozzles, or the spray stays weak after a proper descale. A new head must match the thread on your arm and, for an electric shower, it must be one the manufacturer approves for the model, because some are designed for the unit’s low-pressure flow.
Testing the shower after cleaning
Switch the water back on slowly and let it run for a minute or two with the head pointing at the wall of the tray, so loosened scale and acid residue flush away. Look for leaks at the joint, even drops that appear a few minutes later. Then check the spray: all nozzles should deliver a similar stream, and the pattern should be even.
On a multi-function head, switch through every setting, because each uses a different set of nozzles. If a setting is weaker than the others, repeat the soak with that setting selected, or clear its nozzles by hand with a toothpick. If the water smells of vinegar, it will fade within a minute of running.
Finally, dry and polish the face. Chrome and stainless finishes show every spot of water, and a quick wipe with a dry microfibre cloth gives a lasting shine and slows the return of scale.
Three questions people ask
How often should I descale a shower head?
There is no single answer, because it depends on how hard your water is and how often you shower. A good rule is to clean it when you notice a weaker or uneven spray, or white scale on the face, instead of by the calendar. Hard water areas may need it every month or two, and soft water areas far less often.
Is it safe to leave a shower head in vinegar overnight?
It is not recommended for most metal or coated finishes. Acid left on brass, nickel and coated surfaces for hours can dull, pit or stain them, and rubber seals can harden. Plain plastic and chrome tolerate longer soaks better, but check the maker’s instructions first. For heavy scale, repeat a shorter soak instead.
Does cleaning a shower head improve water pressure?
Often yes, when the cause is blocked nozzles or a clogged filter. Clearing the scale restores an even spray and the pressure you feel usually improves. If it is still weak afterwards, the problem is probably elsewhere, such as a partly closed valve, a blocked filter in the shower unit, or a supply problem, and a plumber can check it.
