Symptoms
- Extra force needed to turn the handle
- Handle feels gritty or catches partway
- Stiffness worse on hot side (more scale from heat)
- Handle used to turn smoothly
Likely causes
- CommonMineral scale buildup inside the valveHard water deposits accumulate around moving parts.
- CommonDried-out lubricant on the stem or cartridgeFactory grease wears away over years of use.
- PossibleWorn or damaged cartridgeInternal wear can make the mechanism bind.
- PossibleCorroded stem threads (compression faucets)Rust or scale on threads increases turning resistance.
What to do
- Turn off the water supply under the sink and relieve pressure by opening the faucet.
- Remove the handle to access the stem or cartridge.
- Wipe away visible mineral deposits and inspect for cracks or grooves in the moving parts.
- Soak metal components (not plastic cartridges) in vinegar to dissolve scale, then rinse thoroughly.
- Apply plumber's silicone grease to the stem threads or cartridge O-rings before reassembly.
- Reattach the handle and test the turning effort; it should move smoothly with light pressure.
- If it's still stiff or gritty, replace the cartridge or stem assembly rather than continuing to force it.
Tools and parts
- Screwdriver
- Adjustable wrench
- Plumber's silicone grease
- Vinegar
Faucet cartridge or stemSearch: “faucet stem replacement kit”
When to call a pro
Call a plumber if forcing the handle risks breaking it, or if a new cartridge doesn't resolve the stiffness.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.