Get to the boat whilst daylight still abounds and have a go at fixing the Webasto. I uncouple the fuel pump, and sure enough diesel is not flowing through the pipework in any fashion that could be described as "easily". I have a try at blowing through the pipe but my lungs aren't up to it, so I get the airbed foot pump on the job. That seems to get things moving, so I put it all back together and give it a go. First attempt does nothing, but then I have just emptied the entire pipe, so I give it another go to give the fuel chance to feed through. Hurray! Soon we have the characteristic concorde-taking-off-in-the-distance whine and all is well. I shall be warm tonight. In time honoured fashion I celebrate with a couple of beers and a kebab by the fire.