TinkerKit Relay

Hi all,
I'm having a bit of trouble using a TinkerKit relay to switch a 24V signal. I have the supply/signal/gnd signals connected to the board and the LED switches on/off depending on the digital state but the relay is not switching when I connect a 24VDC wire to the COM and NC terminals.
Any idea on what the issue might be would be greatly appreciated.
Cheers!

I'm not familiar with the Tinkerkit relay. What voltage is the coil? How much current does it take?
Have you put a reverse bias diode across it to kill the flyback spike?
If so, is the diode the correct way round?
If not, you may have blown the Arduino pin.

Well, magic does happen. After disconnecting and reconnecting everything for the 61st time, it works fine now. No idea how/why but will be keeping an eye on it. Thanks for the help.