Replacement On / Off Valve 18 mm
On / Off shower valve replacement. This part is designed to replace the on/off valve housed generally in the middle of a 3 dial shower valve setup.
The most common symptom you will come across, and reason you will need to replace this part is when your shower is not isolating (shutting water off) to which ever feature is selected on the divertor, instead you will get anything from a slight drip up to running water, even when in the off position.
If you have the larger 24mm on/off valve you can find it here
Please follow the How To Guide on replacing this part here.