A red power light on the BT Business Hub 2 can indicate one of two things depending on whether it's flashing or solid.
Your Business Hub 2 is currently undergoing a firmware upgrade. You must not switch off the hub during this time as you'll break the hub.
Your hub's experienced a major error. The good news is it's normally fixable.
Place a paperclip into the red Reset button on the back of the hub for 10 seconds whilst it's on and connected to the DSL line. Allow the unit to run through the reset process.
If this doesn't fix the hub or the problem persists you may need a replacement hub, in which case you'll need to contact us.