Worcester Bosch 24i boiler ignition going on and off?

I wonder if anybody can help> I have a Worcester Bosch 24i combi boiler. I ahve noticed over the last couple of days that the electronic ignition light on the front is coming on and off in no particular pattern.I can also here a clicking sound. I am not having any problem with the actual heating and hot water but just wondered what the problem is likely to be. Any body got any ideas