How to troubleshoot Moen shower valve

Shower valve has no hot water:

Hot/cold  sides reversed

If you have reversed hot/cold lines, it is because the cartridge installed upside down. To correct the issue, rotate cartridge stem 1800 so that the north is facing down towards the drain.

Leak or drip from the spout

If there is a leak or drip from the spout, it means grommets are not sealing correctly. Replace the cartridge to fix the problem.

The handle is hard to turn

If your Moen shower faucet handle is hard to turn, it is difficult to rotate the cartridge stem. To fix this problem, replace the cartridge or lubricate.

How to install Moen shower valve (Moen T3428, T3238CP, T3429)

To install a Moen two handle thermostatic shower valve, you’ll need the following tools: Then follow these installation instructions:

Install the Shower Arm:

½” copper lookout (pipe protruding from wall) must be 2″ (50mm) minimum to 3″ (76mm) maximum in length and be free from scratches, dents, kinks or bends. The cutoff end must be free of burrs inside and out. Using a tubing cutter is recommended.

To install slip fit shower arm;

If you are using a shower arm adapter-IPS to CC:

Installing the Showerhead:

Attaching Base Escutcheon:

Attach Temperature Knob:

Attach Flow Handle:

How do you adjust a Moen shower valve (Two-handle thermostatic valve)?

To adjust a Moen shower thermostatic valve, follow these steps:

What happens when a Moen shower valve goes bad?

When your Moen shower valve is faulty it may display a number of symptoms, which often worsen with time. Below are some of the signs you could have a bad shower valve that needs to be replaced:

Leaks or drips coming from the spout. Difficulty turning the shower handle, which worsens over time. Hot water suddenly starting to run hotter or water becoming too cold. Slow reaction time when changing water temperature.

New Moen shower valve has no water

If your Moen shower valve has no water, it’s most likely because hot and cold water may not be supplied to the valve. This can happen because of improper use or there is an obstruction in the showerhead/spout. To fix the issue, try these troubleshooting tips:

If you have external shut-off valves, verify they are opened all the way. Make sure there is nothing obstructing the spout or showerhead.

Moen shower faucet won’t turn on

There could be several reasons why your Moen shower faucet doesn’t turn on. The best way to resolve the issue will vary depending on your specific model. Below is how to troubleshoot different Moen shower faucets models that are not turning on.

For Posi-Temp models:

For Moentrol models:

Check this too: Rheem Water Heater Troubleshooting & How to Guide

For ioDigital models:

For ¾” ExactTemp models:

These units must be installed with a volume control valve in addition to the thermostatic valve. The volume control must be rotated counterclockwise to turn the water on. The temperature (thermostatic) handle only adjusts the temperature. This model will have stops located on the valve’s inlets. The stops look like small flat head screws. Use a flat head screwdriver to unscrew this counterclockwise until you reach a stop, this ensures it opened all of the way (screwing clockwise until stop is reached will turn the water off).

Moen leaking shower valve causes and fix

In most cases, leaks are caused by a scratched or torn cartridge, O-ring, or grommet. Replacing the cartridge should fix this problem.