I have a boxer 2014 2.2 hdi. Recently the glow plug light has been coming on for a second time when I turn the key to start the engine-after it has already come on and off with the heating process. It only does it the first start of the morning and the rest of the day the light comes on and goes off as normal. It hasn't been cold and the one morning it was below freezing it seemed a bit more laboured to want to start. The van has done 13000 miles. Does anyone have any ideas. Many thanks. Marcus.