No, not every hose fits every shower head, and the washer depends on which of three connector types you have at each end. UK and EU showers use 1/2 inch BSP thread almost universally, but the sealing method varies: cone washer, flat EPDM washer, or conical nut with built-in seal. Identify the connector before you buy anything, because the wrong washer will leak no matter how tight you get it.
Tools and Parts Checklist
Lay these out before you start. You will not need all of them for every job, but having them within reach saves a second trip.
- Adjustable spanner or 19mm/21mm wrench (hose nuts are usually one of these two sizes)
- Replacement washer set with cone, flat, and conical variants (buy a mixed pack if unsure)
- Old towel or small bucket to catch residual water
- Torch or phone light to see inside the fitting
- Soft cloth for cleaning old sealant residue off threads
- New hose, correct length and connector type at both ends
You do not need PTFE tape for this job if both ends use washer seals. That detail trips people up, and it is covered in the next section.
Identify Your Connector Type First
Unscrew the hose nut by hand or with a wrench and look inside. You are checking the shape of the sealing surface, not the thread, since the thread is almost always 1/2 inch BSP on both the wall outlet and the shower head inlet in UK and EU installations.
| Connector Type | How to Identify | Seals By |
|---|---|---|
| Cone washer | Washer has a raised point or cone shape in the center | Shape, pressing into a matching cone seat |
| Flat washer | Flat rubber or EPDM ring, no raised center | Compression against a flat face |
| Conical nut | The nut itself is shaped like a cone, no separate washer visible | Metal-to-metal or integrated rubber seal inside the nut |
Check both ends of the hose separately. It is common to find a cone washer at the wall end and a flat washer at the shower head end, especially on handset hoses bought separately from the head.
Remove Old Hose: Step-by-Step
Time estimate: 5 to 10 minutes per end, longer if the nut is corroded.
- Turn off the water supply to the shower if there is an isolation valve. If not, be ready to catch a small amount of residual water.
- Hold the wall outlet or shower head steady with one hand so you do not twist the pipework behind it.
- Loosen the hose nut with your wrench, turning anticlockwise. Apply steady pressure rather than sharp force, especially on older chrome fittings that can crack.
- Once loose, finish removing by hand and set the old hose aside.
- Pull out the old washer with a fingernail or small flathead screwdriver. Note its shape before you discard it, this is your reference for the replacement.
- Wipe the inside of the fitting clean. Old washer fragments or mineral scale left behind will stop a new washer sealing properly.
Match Washer to Connector Type
Cone washers seal by shape. The raised cone presses into a matching recessed seat on the fitting, and the seal forms along that contact line. Flat EPDM washers seal by compression, the flat rubber face gets squeezed between two flat metal surfaces when you tighten the nut. These two methods are not interchangeable. A flat washer forced into a cone seat will leak because it cannot fill the angled gap, and a cone washer in a flat fitting has no matching surface to press against.
Conical nuts are different again. The sealing happens inside the nut itself, so there is no separate washer to replace, if that nut is worn or the integrated seal has perished, you replace the whole nut assembly rather than hunting for a washer.
When buying a replacement washer set, get one with multiple shapes included rather than guessing a single type. Most hardware shops and plumbing suppliers sell mixed packs for this exact reason, since the UK market has no single standard connector despite the thread size being consistent.
Install New Hose and Test for Leaks
Time estimate: 10 to 15 minutes including the leak check.
- Fit the correct washer into the hose nut, matching the type you identified earlier.
- Do not wrap PTFE tape around a cone seat or onto a flat washer face. PTFE is for thread seals, not washer seals, and it will interfere with the washer sitting flush. If your installation genuinely needs thread sealant at a threaded joint elsewhere, that is a separate step covered in thread-sealing guides, not this one.
- Screw the nut onto the wall outlet by hand until it stops turning freely.
- Use your wrench to tighten a further quarter turn. That is the standard hand-tight-plus-quarter-turn rule for washer-sealed fittings, go further only if it still weeps under test.
- Repeat at the shower head end with the matching washer type.
- Turn the water supply back on.
This same hand-tight-plus-quarter-turn approach applies broadly to washer-sealed plumbing fittings, including higher-use installations. In commercial settings with commercial touchless faucets, the solenoid and supply connections still rely on correctly matched seals, and over-tightening is one of the more common causes of early seal failure during maintenance callouts.
Once both ends are tightened, run the water for two minutes at both the wall connection and the shower head connection. Watch closely at the nut itself, not just the visible hose. A slow drip often shows up at the one-minute mark rather than immediately, so do not stop checking too early. If you see moisture, turn off the water, dry the fitting, and check that the washer sat flush before you retighten.
Time Estimate by Connector Type
| Connector Type | Removal | Installation | Notes |
|---|---|---|---|
| Cone washer | 5 minutes | 5 minutes | Fastest if the old cone seat is undamaged |
| Flat washer | 5 minutes | 5 minutes | Check the flat face for scale buildup before fitting new washer |
| Conical nut | 5 to 10 minutes | 10 minutes | May need a full nut replacement rather than just a washer |
Add 5 to 10 minutes per end if the old nut is corroded or stuck, since you will spend extra time working it loose without damaging the chrome finish.
If you have tightened a quarter turn past hand-tight and it still drips after the two-minute test, stop and check the washer seated correctly rather than overtightening further. Overtightening a cone washer can crack the seat, and overtightening a flat washer can compress it permanently out of shape. If the fitting itself looks corroded, pitted, or the thread is stripped, replace the wall outlet or shower head rather than fighting the connector, and if you are not confident diagnosing a worn valve or diverter behind the fitting, that is a separate job worth calling a plumber for.