Why this happens

Moen says a hard-to-operate handle usually comes from sediment or debris in the cartridge, mineral buildup or a damaged seal. For a Posi-Temp shower valve, its fix is to replace the 1222 cartridge rather than regrease it. The same cartridge is what Moen replaces when a Posi-Temp valve leaks.

How to fix it

Shut off the water to the shower. Cover the drain.
Remove the handle and trim, then the retaining clip.
Remove the old 1222 with a cartridge removal tool. Note how it faced.
Install the new cartridge the same way, reinstall the clip and trim, and turn the water on.
Check the hottest setting with a thermometer and keep it at 120F or less, adjusting the limit stop by following your valve's guide.

When to stop. If the cartridge will not come out with the removal tool, stop. A damaged valve body means opening the wall.

The part that fixes it

Replacement for Moen 1222 Posi-Temp Cartridge with Removal Tool

1 pack on Amazon 2 pack on Amazon

FourHome is our own brand of replacement parts; this site is published by the team behind it. We earn from purchases made through this link.

Cartridge Removal Tool for Moen 1222 Posi-Temp

10 pack on Amazon

FourHome is our own brand of replacement parts; this site is published by the team behind it. We earn from purchases made through this link.

Not sure which part you have? Pull the old one and match it by brand, length and broach on Stems & Cartridges, an identification index of faucet stems and cartridges by part number.

If this does not fix it, tell the plumber

It is a Moen Posi-Temp single-handle shower that is hard to turn.
Whether you replaced the 1222 cartridge.
Whether the shower has its own stops.

Build the full list: what to tell the plumber.

Start this troubleshooter over

References (every fact above comes from one of these pages)

Vent, Valve & Volt is published by the team behind FourHome. Browse all FourHome replacement faucet and shower parts on the FourHome Amazon store.