Ring 150 and select faults option, Einstein will send another hit to your box. Sometimes the system can take 3 hours for the hit to send as the main box gets hit first and others sit in a queue for the signal to hit.
Your main box will be showing green on the system whilst the slave box will show up red.
The hit goes down the RF cable, so ignore those saying it goes via the Internet etc as they will be talking out of their pants.
Feel free to click on the thumbs up thingy and kudos thing. It really helps me to feel important and boosts my ego. Seriously though, I'm happy to help.