Heating Fixed

Got the heating fixed this afternoon.  As I suspected it was the control board, but much against my expectation the engineer had a spare in the van!  

This is the header tank, where he fixed the ball cock.  When I was trying to figure out what was wrong and checking everything I noticed it wasn't working, so it's good to get that done at the same time.  He had the spare parts for that in the van too.  Amazing.