How to Replace a Moen 1225B Shower Cartridge | Fix a Leaking Shower, by Kitchen Faucet on YouTube. 3 min 2 s.
- Video length
- 3 min 2 s
- Time to do it
- 30 minutes
- Difficulty
- Medium
- Steps
- 8
What you need
Steps
Shut off the water at the main valve or at the shutoff stops on the shower valve. Open the handle to drain the pressure and let the last of the water run out.
Pry off the small index cap on the handle with a flathead screwdriver, undo the screw underneath, and pull the handle straight off the stem.
Remove the trim plate or escutcheon so you can reach the valve body, then pull out the U-shaped retainer clip that holds the cartridge in place.
Grip the old cartridge with pliers and pull it straight out. If it will not budge, thread on a cartridge puller and turn it out slowly instead of forcing it.
Wipe the inside of the valve body clean and check for grit or scale. A quick flush of the open valve helps clear loose debris before the new part goes in.
Coat the new cartridge O-rings with a thin layer of silicone plumber's grease, line up the tab on the cartridge with the notch in the valve, and push it in until it seats.
Refit the retainer clip fully into its slot, then put the trim plate and handle back on and tighten the handle screw.
Turn the water back on slowly and run the shower. Check around the trim for drips, test hot and cold both ways, and tighten anything that still weeps.
Tips and common mistakes
Check the number stamped on the old cartridge before buying, so you get the right Moen part.
Never hammer the cartridge in. If it will not seat, the tab is misaligned or the valve body still has debris inside.
Turn the water on gradually after the repair so you do not shock the new O-rings.
Keep the towel under the valve while you work, since the valve body holds a little water that will spill out.
Questions
How do I know if my shower uses a 1225B cartridge?
Take the old cartridge out and look for the number stamped on the plastic body. Moen single-handle valves that take a 1225 or 1225B look the same, and the 1225B is the newer version of that part.
Do I have to shut off the main water supply?
Not always. Many Moen valves have their own shutoff stops behind the trim plate. If yours does not, close the main valve for the house before you start.
Why is my shower still dripping after the replacement?
The usual causes are a retainer clip that is not fully seated, grit trapped under the O-rings, or grease missing from the new cartridge. Pull the clip, rinse the valve body, and reseat the cartridge.
This guide was drafted from the video's details and general task knowledge. It has not been checked against the full video. Check the video and relevant product instructions before following a procedure. Report a correction.
