As part of a decoration project I'd like to replace the tatty old switch for my immersion heater. It is a small square plate with a red light bar above the switch and the words Hot Water below - must be over 20 years old. Can I just replace the switch plate without buying a new back box? If so, would the new plare also have to have the light bar above the switch, or could I use one where the switch itself has a light on it (like the one Screwfix is selling)? Is this a simple task - will it be obvious to a beginner how to connect new plate?
It is your choice what you have, as for if the patress needs changing that depends on what you have, and what you get. Some of the older ones have rounded corners, the newer ones have more "square" corners.
Regarding the switch itself, there is a wide variety, but bear in mind it is NOT a light switch, but a dedicated immersion heater switch, so long as you get one for an immersion heater it should not be a problem.
When you change it, turn the main consumers unit(s) off to be 100% sure the electricity is off, I would also suggest you do it in daylight.
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