Which RCD are you talking about? If you mean the one in the garage then, as has been implied, you wouldn't expect the test button to (currently) do anything - since the test facility relies on their being electricity available, and none is currently getting to your garage.OK one thing that I'm not sure about is on the RCD it has a test button. I thought when you pressed that it is supposed to make the switch flick off. Is this correct? If so we have a problem because it doesn't. Does this suggest there is no power to the RCD?
Kind Regards, John
Both RCD test buttons don't work. This is a bit worrying as the power to the first RCD comes straight from the electricity meter, no way of isolating it to look for a loose connection.