Moen’s Posi-Temp shower valve is known for being simple, reliable, and anti-scald. But even solid hardware can act up over time. If your Moen shower is giving you trouble—like no hot water, poor pressure, or a stiff handle—you’re not alone. These are common problems, and most of them can be fixed without tearing down tile or calling a plumber.
Let’s go over the most common Moen Posi-Temp valve issues and how to fix each one.
1. No Hot Water or Only Lukewarm Water
This one frustrates a lot of homeowners. You turn the handle expecting hot water—but it only gets warm, or worse, stays cold.
Likely cause: The temperature limit stop (aka “hot limit safety stop”) might be set too low. This piece limits how far the handle can turn toward hot, especially in homes with young kids.
How to fix:
- Remove the handle and escutcheon plate
- Look for a white or gray plastic gear on the cartridge stem
- Pull it out, rotate it slightly counter-clockwise, and reinsert it
- Reassemble and test water temp
Still no hot water? You might need to replace the cartridge (see below).
2. Stiff or Hard-to-Turn Handle
Over time, mineral buildup or worn seals inside the cartridge can make the handle tough to turn. If you feel resistance, grinding, or it just feels “off,” the cartridge is probably the issue.
Fix: Replace the 1222 cartridge (standard for Posi-Temp valves).
Steps:
- Turn off water supply to the shower
- Remove the handle and trim plate
- Use pliers to slide out the retaining clip
- Use a Moen cartridge puller to remove the old one (they can be stubborn)
- Insert new cartridge with the notches facing the correct way
- Reinstall clip, trim, and handle
Pro tip: use plumber’s grease on the new cartridge O-rings before inserting—it’ll slide in easier and last longer.
3. Water Keeps Dripping After Shutoff
If your shower continues to drip for minutes after turning it off, the cartridge likely isn’t sealing fully.
Minor dripping right after a shower (a tablespoon or two) is normal. But if it keeps dripping for hours, it’s time for action.
Fix: Replace the cartridge. (Same steps as above.)
Also check that the retaining clip is fully seated—if it’s not locked in, the cartridge can shift and leak.
4. Uneven Water Temperature or Sudden Fluctuations
One of the Posi-Temp’s main jobs is to keep temperature consistent—even if someone flushes a toilet while you’re showering. If you’re feeling random surges of hot or cold, the valve isn’t balancing correctly.
Causes:
- Cartridge is gummed up or sticking
- Debris or mineral deposits inside the valve body
Fix:
- Remove the cartridge and flush the valve body with the water briefly on
- Inspect and clean any debris or scale buildup
- Replace the cartridge if it’s worn or cracked
5. Low Water Pressure
If the pressure feels weak from the shower head, but fine elsewhere in the house, the valve or cartridge may be restricted.
Fix:
- Check for debris in the cartridge or valve body
- Clean or replace the cartridge
- Make sure water supply valves (behind the wall or in a panel) are fully open
6. Handle Spins All the Way Around
On a properly working Posi-Temp, the handle should only rotate about 270°—from full cold to full hot. If yours spins freely in circles, something is loose or broken inside.
Fix:
- Check the handle screw—it may just be loose
- If the stem is worn or broken, replace the cartridge
- Also inspect the plastic limit stop—it may be broken or missing
Tips to Avoid Future Problems
- Flush your plumbing system once a year to prevent mineral buildup
- Use a water softener if your water is hard
- Turn the handle gently—avoid yanking or forcing it
- Replace cartridges every 5–10 years or sooner if performance drops
Final Thoughts
Most Moen Posi-Temp valve problems trace back to the cartridge. The good news? It’s replaceable in under an hour—and Moen even offers free replacements if you’re the original owner.
If you’ve got water that won’t get hot, a handle that sticks, or a shower that sounds like a lawn sprinkler, don’t stress. A simple cartridge swap, vent cleanout, or adjustment can usually get things back on track.
And hey—if you need peace of mind, just take a picture of your valve and bring it to the plumbing aisle. Most hardware store staff can point you to exactly what you need.