Known problems with Moen faucets include leaks from the spout or handle, difficulty operating the spout or handle and incorrect water temperature. Tips and troubleshooting advice for these known problems can be found in the user manual or on the official Moen website.
Should a Moen faucet experience leakage from the end or bottom of the spout or from the handle, it is usually due to a scratched o-ring or grommet on the cartridge. This problem can be easily fixed by replacing the cartridge on one-handle spouts or cartridges on two-handle spouts. Occasionally, the problem may also be due to a faulty part in the mechanism. If this is the case, replace the faulty part and the faucet should stop leaking.
If the handle or spout is difficult to operate, the cause may be from debris or sediment in the cartridge or a damaged seal. Replacing or servicing the cartridge should solve this problem. However, it is also worth checking to see if the handle mechanism is correctly installed or if the handle feels loose to the touch. Problems with the water temperature are generally the result of debris or some other form of obstruction in the balancing spool or an incorrectly calibrated valve. Replacing the cartridge and cleaning the valve generally rectifies this issue.