Leaking Shower Head: Why It Drips After Use

Is the drip normal, or is something letting water through?

Every shower holds some water after you switch it off. It sits in the hose, in the head and, on an electric shower, in the small heater tank inside the unit. That water runs out slowly through the spray holes, so a steady drip that slows down and stops within a few minutes is normal. Large fixed rain heads on a rigid riser hold more and can drip for longer.

The quick test is to time it. Turn the shower off, note the time and come back after ten minutes. If the drip has stopped, there is nothing to fix. If it is still dripping at the same speed, or you find a wet tray in the morning, water is coming through a valve that should be shut. That is a slow leak rather than drain-down, and it will not fix itself.

The other thing to check is where the water appears. Water from the face of the head only is a valve problem. Water spraying or weeping from the ends of the hose, or from where the head screws on, is a washer or seal at that joint, and that usually only shows while the shower is running.

Find the source in this order

Work from the cheapest, easiest cause to the most involved. Most of these checks take a few minutes and need no tools beyond an adjustable spanner and a flat screwdriver.

• Run the shower and watch both hose ends and the head connection. A spray or trickle there points to a perished hose washer or a split hose
• Turn it off and time the drip. Stopping within a few minutes means it is only drain-down
• Look at the spray face. Heavy white scale or blocked nozzles can make a head spit and dribble unevenly after use
• Close the isolation valve on the shower supply, usually a small slotted valve on the pipe near or behind the unit, then let the head drain. If the drip stops for good, the valve is letting water past
• Note what kind of shower you have, because the valve fault and the fix are different for mixer and electric showers

On an electric shower, switch off at the ceiling pull-cord or wall isolator and at the consumer unit before removing the cover. There are mains-voltage parts inside.

Mixer showers: a worn or scaled cartridge

On a thermostatic bar valve or a concealed mixer, the flow is shut off by a cartridge behind the control handle. Most modern ones use a pair of ceramic discs that slide over each other. When grit or limescale gets between the discs, or they wear, they no longer seal completely, and water seeps through to the head even with the control in the off position. London’s hard water makes scale a common cause.

Older manual showers, and some two-handle mixers, use a rubber washer on a rising spindle instead, just like an old-fashioned tap. When the washer hardens and flattens, the valve drips. That is a cheap part, and the same fault that makes an old tap drip from the spout: see tap washer replacement.

The fix is almost always a replacement cartridge rather than a new valve. The hard part is getting the right one: cartridges are brand and model specific, and the model name is usually on the valve body, the back of the handle or the installation leaflet. As a typical market guide, a genuine replacement flow or thermostatic cartridge costs roughly £40 to £200 as a part, and some premium brands charge more.

Do not try to free a stiff cartridge by forcing the handle past its stops. On a concealed valve behind tiles, a snapped spindle can mean cutting tiles to reach the valve body, which turns a cartridge swap into a much bigger job.

Electric showers: the solenoid valve

An electric shower is fed straight from the cold main, and the flow is opened and closed by a solenoid valve inside the unit. When you press stop, the solenoid should shut the water off completely. Limescale on its seat, or a worn diaphragm, lets a little water through, which then trickles out of the head after every use and often overnight.

A short drip after switching off is normal on an electric shower, because the heater tank drains through the head. A drip that carries on long after that is the solenoid. A replacement solenoid is typically a £20 to £60 part, but fitting one means opening a unit that has mains electricity and water in the same box, so it is a job for someone competent with both.

If water comes out of the bottom of the unit rather than the head, that is usually the pressure relief device. It is a safety part that lets water out if the outlet is blocked, often by a badly scaled head or a kinked hose. Stop using the shower, then descale or clear the head and straighten the hose so it does not happen again. On most showers a PRD that has vented has to be replaced, which means opening the unit, so switch off at the isolator and treat it as a job for someone competent with electrics. If the shower has also stopped heating or will not start, see electric shower stopped working.

Fixes you can do at the head and hose

Unscrew the head from the hose and check the flat rubber washer inside the nut. If it is missing, split or squashed thin, replace it. Most UK shower hoses and heads use standard half-inch threaded connections, so washers and hoses from a plumbers’ merchant usually fit. A new hose typically costs £10 to £30 and a new head £15 to £60.

To descale a head, soak it in a descaling solution or white vinegar, then rub the rubber nozzles with your thumb to push the scale out. Rinse it well before refitting. If the hose is split, bulging or stiff, replace it rather than patching it.

None of these will stop a drip that comes through a passing valve. If the isolation valve test showed the valve is the cause, the fix is inside the shower. If the isolation valve itself is dripping from its spindle, see isolation valve leaking.

When to call someone, and what it involves

A dripping head is rarely an emergency, unlike the leaks in when a broken shower needs fixing tonight. It wastes water, which you pay for if you are metered, and it leaves scale and staining in the tray. It becomes urgent when the water is going somewhere it should not: behind tiles, through the ceiling below, or out of an electric shower casing. Water behind the valve or around the tray is a different fault, covered in shower leaking.

A plumber isolates the supply, takes the handle and trim off, identifies the valve and swaps the cartridge, washer or solenoid. On most showers that takes under an hour once the right part is in hand. If water is coming through a ceiling now, book an emergency leak repair: you pay the £60 call-out and the repair price is agreed with you on site before any work starts.