Replacing a monobloc mixer tap cartridge
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Most likely cause & what to check
A monobloc tap has a single lever that controls both temperature and flow. Inside is a ceramic disc cartridge — typically 35mm. When stiff, dripping, or leaking it needs replacing.
Close both isolation valves under the sink. Open the tap to release pressure.
Look for a decorative cap on the handle — prise it off with a flat blade to reveal a screw. Remove the screw, then pull the lever off.
Unscrew the large chrome shroud or collar beneath the lever (hand-tight usually). The cartridge retaining nut is now visible — unscrew it.
Pull out the cartridge and note the brand markings (Sedal, Kerox, and Galatrek are common brands). Replacement cartridges are available from plumbers' merchants for £8–£30.
Install the new cartridge, ensuring the locating pin aligns with the body. Reassemble in reverse order and test slowly — check for leaks at the handle before replacing all cosmetic parts.
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