So, this morning, I switched on my headlights to set off for work. Nothing! Sidelights came on. Switching on full beams worked. But no dipped beam. 
Text message to customer to say I couldn't make it by 7.30 as had to drive along a fairly main bypass and didn't want to chance it with sidelights only.
I have removed both headlights...Thank you Citroën for making that finger-smarting in the cold 
They are these type of headlights:
I assume the coil with the shield behind it is DippedBeam and the one without is MainBeam. I think I can see some damage to the DB coils in each but I can't see any scorch marks or anything such. The MB coils look unscathed.
So, hopefully just a case of replacing the bulbs. However, I'm just a bit suspicious that both have gone at the same time. Usually, just one goes, you drive around for a few days looking like a huge motorbike and buy a spare when you're passing a Halfords. Would all the lights be on the same circuit? i.e. if the DB circuit had a problem, then I assume the MB wouldn't work either?
And before anyone asks, yes, the heated wing mirrors are working just fine.
