Family members have bought a house to rent out. Owner used to be an electrician, not currently registered, and happily retired. We got told that a new RCD box is needed ideally, though current situation is legal. Got quoted £300-£350, which, from my research online, is reasonable for the North West. Got told it's several hours work. Now 'family member' has found an RCD box, of an apparently good brand, for £21 from a shop (I am surprised, as we paid £80 ish for similar sized house RCD box). And he says he can install it in under an hour. Couple of questions: - Why are people wanting to spend a few hours on this when someone can do it in an hour? What else are they doing, and is this necessary? - Should 'family member' go ahead and do it himself, is this legal? All honest feedback appreciated - don't shoot the messenger and all that I am very happy to be educated on this. Thanks.