Clogged Showerhead Nozzles: Descaling Step by Step

The showerhead is one of the worst spots for scale in the bathroom: hot water, tiny openings, and a little water left in every hole after each shower. Over time the nozzles gradually close up. The good news is that a clogged showerhead is easy to fix once you know the cause and the right method.

Why showerheads clog

Tap water carries dissolved calcium, magnesium, and bicarbonate. Heat makes calcium bicarbonate break down into insoluble calcium carbonate more readily, which is why water heaters and showerheads scale up much faster than cold taps.

When you turn the shower off, a little water stays in the nozzles. As it evaporates, calcium carbonate settles on the rim and walls of each hole, a thin layer per shower. Nozzles are only about a millimeter across to begin with. After a few months they narrow and warp, the spray goes crooked, and eventually some close off entirely.

Besides scale, debris from the pipes can clog a showerhead. After a renovation, a plumbing repair, or in older galvanized pipes, sand, rust, and bits of gasket can wash into the showerhead and lodge in the inlet screen or behind the faceplate.

Five steps to diagnose and fix it

Not every deposit on a showerhead is white. Reddish-brown flecks usually come from rust or sediment in older iron pipes, and gritty specks behind the face plate after plumbing work are typically sand or bits of pipe sealant. A descaler dissolves calcium and magnesium scale, but it won't do much for sand or debris. That's why the inlet screen check in the diagnosis above matters: if you find grit there, rinsing the screen fixes the problem and no soak is needed.

How a descaler works

Calcium carbonate doesn't dissolve in water and isn't bothered by alkalinity, so soaking in water or scrubbing with dish soap won't help. Acid dissolves it: hydrogen ions react with calcium carbonate to form water-soluble calcium salts, water, and carbon dioxide. The tiny bubbles you see on the faceplate during a soak are that reaction.

Take CleenU Faucet & Sink Scale Remover as an example. It's an acidic descaler, pH 1.5 to 3.0 as supplied, made with mineral and organic acids, a corrosion inhibitor, and a wetting agent, and it's unscented. The acids dissolve the scale; the wetting agent helps the liquid get into narrow nozzles instead of sitting on the surface; the corrosion inhibitor protects chrome and stainless. Aerators and showerheads can soak in a 1:1 mix with water for 15 to 30 minutes.

It isn't for marble, limestone, or cultured marble sinks, soaking coated hardware or brass, or aluminum, and it must never be used with chlorine bleach. For gold, matte black, brushed, or other coated showerheads, shorten the soak and test on the back first.

Descaling a showerhead, start to finish

Remove the showerhead. Handheld heads usually unscrew from the hose by hand; for fixed heads, follow the manual. If it's stuck, wrap it in a towel before using a wrench so you don't scratch it.

Mix the soak. In a container, combine descaler and water 1:1, enough to fully cover the faceplate.

Soak 15 to 30 minutes, face down. You'll see small bubbles rising.

Rub the nozzles. Many showerheads now have soft rubber nozzles; after soaking, rub each one back and forth with a fingertip and the softened scale squeezes out. Brush hard nozzles with an old toothbrush. For a stubborn hole, ease a fine needle in gently without forcing it wider.

Rinse. Rinse the showerhead inside and out, reconnect it, and run water for a minute or two to flush out loosened bits.

For fixed heads that won't come off, fill a plastic bag with the 1:1 mix, slip it over the head so the face is submerged, secure it with a rubber band, then remove it after the soak and run the water.

For faucets and other fixtures, see How to clean a bathroom. To tell scale from soap scum, see Soap scum vs. hard water stains.

Adjust the soak to the finish

Showerheads all look shiny, but they're built very differently, and that changes how long and how much you soak.

Chrome-plated plastic is the most common. The body is engineering plastic with a thin electroplated chrome layer. If the plating is intact, a 1:1 soak for 15 to 30 minutes is fine. If it's already peeling, acid can creep under the edge and lift more of it, so soak only the spray face and rinse right away.

Stainless steel and chrome-plated brass hold up better to acid and can take the normal soak time. A descaler with corrosion inhibitors is gentler on the metal than plain vinegar or citric acid.

Gold, matte black, gunmetal, and brushed finishes are usually painted or PVD-coated, and those aren't on the descaler's list for soaking. Let only the spray face touch the diluted solution, cut the time to 5 to 10 minutes, test a hidden spot first, and check the color after rinsing.

Silicone nozzles inside the face plate don't mind acid at all. Soaking and then rubbing them with a fingertip is the easiest way to clear them.

How to tell it worked

Reinstall the head and run the water. Check three things: the spray goes straight down instead of sideways, every nozzle is flowing, and the face feels smooth with no grit. If all three check out, you're done.

If most nozzles are back but one or two are still blocked, the scale in those holes didn't fully soften. Soak just the face for another 10 minutes and rub them again. If you've done two rounds, the white crust is gone, and the spray still veers off, the nozzle itself is probably deformed or the face plate is damaged. More soaking won't fix it, and a new showerhead is the faster answer.

Common mistakes

Soaking the whole hose. The braided hose doesn't need descaling, and a long acid soak isn't good for the fittings.

Leaving it for hours to speed things up. For heavy scale, two shorter soaks with a scrub in between are safer and work better than one very long one.

Widening holes with a needle. An enlarged hole sprays harder than its neighbors and makes the pattern messier, not better.

Skipping the flush. Softened scale left inside the head gets carried to the back of the nozzles and clogs them again quickly.

Keeping your showerhead from clogging

After each shower, rub the rubber nozzles with a fingertip and wipe the faceplate dry.

In hard-water areas, soak and descale monthly; thin scale clears in about 15 minutes.

After plumbing work, run the water for a few minutes before reattaching the showerhead so debris doesn't get trapped.

Consider a whole-house or water-heater softener to cut scale at the source.