When we switch the tap from Bath to shower, water squirts from the connection of the shower head. I thought this would be a case of a warn washer or O-ring. When I unscrewed the hose there wasn't a washer or ring. Should there be. The mixer is as in the image.
1. Sone don't (e.g. Architekt), and seem to work OK. 2. But there shouldn't be any harm in fitting a 1/2" rubber shower hose washer such as Screwfix 3841J.