Why does my shower water smell? Causes and simple checks

Why does my shower water smell? Usually because of chlorine, which hot water releases, or a smell from the drain, stale water in little-used pipes, or rubber and plastic parts in your plumbing. Most of these are easy to check at home, and your water company can help if a smell persists.

This guide explains what each smell usually means, the checks that find the cause and when the Drinking Water Inspectorate (DWI) says to contact your water company. For what a filter shower head does and doesn't do, see our complete guide to filter shower heads in the UK.

We sell a filter shower head, which is designed to reduce free chlorine, not to fix smells, so every figure here links to its source.

What does the smell in your shower mean?

The smell in your shower usually points to its cause. Chlorine smells like a swimming pool, drains smell eggy, stale water smells musty, and rubber or plastic parts can give an antiseptic, TCP-like smell.

The DWI says traces picked up from your own plumbing, fittings or appliances are the most common cause of unusual tastes. Reports are rare: in 2024, water companies in England and Wales were contacted about the taste or smell of tap water 2.7 times per 10,000 people, according to DWI figures published by Discover Water.

The sections below take each smell in turn, then the checks that narrow down the cause.

Why does my shower smell of chlorine?

A shower smells of chlorine because hot water can't hold as much chlorine as cold, so the chlorine escapes as the water leaves the shower head. Bristol Water says the smell can be particularly noticeable with a combi boiler or electric shower, which heat the water directly.

The chlorine is there on purpose. Water companies in England and Wales must disinfect the supply, and the DWI says they typically keep the residual at 0.5 mg/l or less, a level it calls perfectly safe to drink.

The level also moves around. Severn Trent says chlorine can be more noticeable near a treatment works and first thing in the morning or early evening, and that cold water holds chlorine for longer than warm water. The DWI links an occasional slight chlorine smell to maintenance work and says it is no cause to worry.

Some people choose a filter shower head designed to reduce free chlorine. That is a preference, not a safety step, and we make no claim that a filter changes how your shower smells. The DWI notes that the residual can be free or combined chlorine; we make no claim about combined chlorine, also called chloramine.

Why chlorine is in tap water at all, and how much reaches your home, is covered in chlorine in UK tap water: why it's there and how much.

Why does my shower smell of rotten eggs?

A rotten-egg smell in the shower usually comes from the drain, not the water. Northumbrian Water says such smells are probably stale air trapped in a sink's waste and overflow, and that running water disturbs the odours.

Showers are no exception. Severn Trent lists the traps on sinks, wash basins, baths and shower trays among the causes of sewage-like smells, says household drain cleaning products can clear or unblock a drain, and advises calling a plumber if the smell doesn't subside.

The glass test

The DWI's check is simple. Fill a glass with water, take it into another room and smell it again. If the smell has gone, the sink or drain is the likely cause and should be cleaned or unblocked. If it's still there away from the sink, the DWI says to contact your water company immediately.

Only from the hot tap?

If the eggy smell comes only from the hot water, Northumbrian Water points to the hot water system. That can happen when the thermostat is set too low, or when the system hasn't been used for a long time. Heating the water up and running it through should clear the smell; if it doesn't, ask a plumber or heating engineer to check the system.

Why does my shower smell musty or earthy?

A musty or earthy smell usually means water has been standing in little-used pipes. The DWI says water left to stand for a long time, or warmed in little-used sections of plumbing, can pick up this taste, and that the cause is harmless and naturally occurring.

That fits a spare-room shower or a home left empty over a holiday. Thames Water suggests running your cold taps for around five minutes if your property has been empty for a while, and insulating pipes so hot water pipes don't warm the cold ones.

Sometimes the cause is the source water. About half of our drinking water comes from rivers and reservoirs, the DWI says, and in summer these can develop a musty or earthy smell, commonly from algae growing in reservoirs. Water companies are required to treat these tastes, though the DWI notes that occasionally, especially in exceptionally hot weather, the treatment is not optimal.

If your neighbours notice the same smell, the cause is less likely to be your own plumbing, so let your water company know.

Why does my shower water smell of plastic or rubber?

A plastic, rubbery or TCP-like smell usually comes from chlorine reacting with rubber or plastic parts in your plumbing. The DWI says these reactions can give antiseptic or medicinal tastes that are not harmful at the levels usually seen in tap water but can be very unpleasant.

Thames Water lists materials chlorine can react with, including tap washers, plastic kettles, washing machines, dishwashers, appliance connection hoses, rubber anti-splash attachments and plastic pipework. The DWI says a common cause of TCP-like tastes is the hoses that connect appliances to the water supply.

A shower has rubber and plastic parts of its own, such as the hose and its washers. If the smell comes only from the shower, not from the cold kitchen tap, those parts are the first place to look, especially if one was changed recently.

Discover Water notes that home plumbing can cause a range of tastes, including metallic, salty, rubbery and earthy ones. If a smell stays, the DWI says your water company can help you find out whether anything is wrong with your plumbing, or you can ask a WaterSafe-approved plumber.

How to find where the smell is coming from

Five quick checks usually show whether a smell comes from the water, your plumbing or the drain. Work through them in order, and note what you find in case you need to call your water company.

1. Hot or cold? Smell the cold water, then the hot. A smell from the hot water only points to chlorine escaping or, if it's eggy, to your hot water system.
2. Other taps? The DWI's first step is to check other taps in your home, to see whether more than one is affected.
3. Away from the drain? Take a glass of water into another room and smell it again. If the smell goes, the drain is the likely cause.
4. Run it through. Run the tap or shower for a few minutes to bring fresh water through; the DWI says this should clear stale water from little-used pipes.
5. Ask a neighbour. The DWI's next step is to check with your neighbours, to see whether the problem is confined to the plumbing inside your home.

If the smell comes from one tap or shower only and fades away from the plughole, the cause is probably in your home and fixable.

When should you contact your water company?

Contact your water company if a smell is particularly bad or strong, makes the water unpalatable, or is new and doesn't go away in a short time, the DWI says. For a suspected fuel spill or leak, contact your water company and your local authority straight away.

The DWI also says to contact your water company immediately if a rotten or stagnant smell is still there when you take a glass of water away from the sink. When you call, it suggests having three things ready:

• a description of the taste, the smell or both;
• whether it affects other taps in your home or neighbouring properties;
• when you first noticed the change.

A faint chlorine smell usually doesn't need a call. Yorkshire Water says water that tastes faintly of chlorine isn't unsafe and usually returns to normal within hours or days, and asks customers to get in touch if the taste lasts more than five days.

What a filter shower head can't fix

A filter shower head is not a fix for shower smells. It is designed to reduce free chlorine, and we make no claim about smell; drains, hot water systems, stale water and rubber or plastic parts need the checks above.

Waterhush reduces free chlorine, and that is the only claim we make. We make no claim about smell or about chloramine, and a filter won't change a smell that starts in a drain, a hot water cylinder or the pipework.

The Waterhush Shower Kit needs a shower with a hose outlet. Its thread size isn't confirmed yet, so contact us if you're unsure it will fit. It is not for electric showers unless your shower's manufacturer confirms in writing that a filter head can be fitted to your model; filter shower heads and electric showers explains why.

Whether shower filters do their job at all is a fair question. The evidence, and its gaps, are set out in do shower filters work? What the evidence really says.

A filter is never a reason to skip a call, either: a strong, new or fuel-like smell is one for your water company.

The bottom line

Shower water usually smells because of chlorine released by hot water, a drain, stale water in little-used pipes, or rubber and plastic parts. A glass of water taken to another room, a check of other taps and a few minutes' running will find most causes. If a smell is strong, new and lasting, or like fuel, contact your water company. A filter shower head is designed to reduce free chlorine; it is not a fix for smells.