What could be the problem if water is continuously running from shower head but turned off?

There could be several reasons why water is continuously running from a shower head even when it is turned off:

1. Faulty Shut-Off Valve: The shut-off valve, which is usually located behind the shower head, may be faulty or defective. This can cause a constant flow of water even when the shower handle is turned off.

2. Worn-Out Washer: The washer inside the shut-off valve can become worn out or damaged over time, leading to a faulty seal and allowing water to seep through.

3. Damaged Cartridge: Some shower faucets use a cartridge instead of a traditional shut-off valve. If the cartridge is damaged or not seated properly, it can cause a steady flow of water.

4. Debris or Sediment Build-Up: Accumulation of debris, sediment, or mineral deposits in the valve or shower head can interfere with the proper functioning of the shut-off mechanism.

5. Incorrect Installation: If the shower head or valve was not installed correctly, it may not seal properly, resulting in continuous water flow.

6. High Water Pressure: In some cases, excessively high water pressure may overcome the ability of the valve to completely shut off the water flow.

To address this issue, you can start by checking the shut-off valve behind the shower head. If it's faulty or damaged, you may need to replace it. If the problem persists, you might need to disassemble and inspect the valve or cartridge for any damages or blockages. In case of more complex issues, it's best to consult with a qualified plumber for proper diagnosis and repair.