Can someone please explain the difference between an isolating valve and a service valve. Which one should I use for an electric shower, and are the speedfit ones suitable? Thanks
In principle, they serve the same purpose, but what is usually referred to as a service valve is a small inconspicuous valve that is turned on and off with a screwdriver and an isolator is a larger valve with a handle (either a gate valve or stop tap).
Electric showers can use either a stop tap or service vale.