Common causes of problems with Moen faucets include scratched o-rings or grommets, a broken handle, a faulty rubber seal, a clogged cartridge or an obstructed supply line, states the company. Damaged o-rings are a typical cause of faucet leaks, and can be repaired with replacement cartridges and seals. Faucets may also leak if the rubber spout seal is worn. In some cases, the faucet parts may be faulty and require replacement.
If debris collects in the faucet's supply line or cartridge, the water pressure may become very low from one or both taps. In some cases, simply cleaning out the debris may solve the problem. In others, replacing the diverter may be the solution. If a Moen faucet's pulldown wand comes loose, the cause may be a broken docking collar. An uncalibrated hose or an improperly positioned hose weight may also cause this problem.
Mineral build-up can cause the faucet handle to lock up, making it difficult to move. Damaged cartridge seals can also cause this problem, and may need to be replaced. One-handle faucets may also fall into the "off" position due to a broken connection or a manufacturing defect. Excess silicone inside the handle mechanism can also affect the handle's stability. In some cases, cleaning out the silicone can fix the issue.
Issues with incorrect water temperature may arise with Moen faucets if the balancing spool is stuck within the housing. This problem can be solved by loosening the screws that secure the unit. However, problems with water temperature can also result from inadequate pressure to the hot or cold tap. Additionally, an improperly calibrated valve may cause only cold water to pour from the faucet.