How do I unblock a shower head?

A shower head that sprays sideways or has gone weak is nearly always limescale, not a failing shower. The mineral builds up inside the nozzles and narrows them until the flow distorts. Because it's a mineral deposit, acid dissolves it and scrubbing does not.

What you'll need

• White vinegar or citric acid
• Freezer bag and elastic band
• Old toothbrush
• Adjustable spanner to remove the head (optional)

Step by step

1. Fill a strong freezer bag with white vinegar or a citric acid solution.A tablespoon of citric acid powder in 500ml of warm water works well and doesn't smell.
2. Tie the bag over the shower head so the whole face is submerged.Elastic band around the neck of the bag and the shower arm. Support the weight if the bag is heavy.
3. Leave it for at least an hour — overnight for heavy scale.Contact time is the entire method. Rushing this means scrubbing instead.
4. Remove the bag and rub each rubber nozzle firmly with a thumb.Modern heads have flexible nozzles designed to release scale exactly this way.
5. Brush the face with an old toothbrush and run the shower hot for a minute.This flushes loosened debris out rather than letting it settle back into the nozzles.
6. If the flow is still poor, unscrew the head and check the filter gauze at the inlet.There's usually a small mesh washer that catches grit. It clogs, and almost nobody knows it's there.
7. Rinse the gauze, refit the head with the washer the right way round, and test.Missing or reversed washers cause leaks at the joint.

Tips

• Wiping the shower head face after use, like squeegeeing the screen, prevents most scale from forming in the first place.
• For a fixed head that can't be bagged easily, cable-tie a plastic tub of descaler around it, or use a cloth soaked in descaler wrapped and bagged.
• If the head is old, cheap and heavily scaled internally, replacing it may genuinely be less effort than restoring it.
• Descale the hose too if it's flexible metal — scale collects in the ridges.

Common mistakes

• Poking nozzles with a pin — It enlarges some holes and not others, permanently distorting the spray pattern.
• Using bleach — It does nothing to limescale, which is a mineral rather than organic growth.
• Forgetting the inlet filter — It's the hidden half of the problem, and clearing only the nozzles often leaves the flow poor.

Questions people ask