I'm due to have my inefficient heating boiler replaced this year. We'll see what happens then. It should improve matters. It's unfortunate that my house is a 100 year old "cube" of old fashioned double-brick construction with 9" (around 18cm) solid walls. It is double-glazed, which has improved matters, but you can sometimes feel the coldness on the walls on the north side of the building. We did apply the insulating polystyrene wall covering you can get when we first moved in, but it made no real difference to one of the bedrooms which always seems cool. It never gets any sun.
Still, we shouldn't complain: the last e-mail I had from the other half in Siberia said that it was -30 and due to drop to -35. Ice crystals were hanging in the air, and when he got in his apartment his specs didn't steam up - they froze! He than had to wait for them to warm up a bit more before he could wipe them.
Richard, if this Powergen thing doesn't work out I will keep my eyes open for Southern Counties. I'll give Powergen a fair crack at it first and see what improves. Any of them are better than the bottled gas we had to use before they connected our village to the mains! I use as many low-energy bulbs as I can, and I think that is paying off. Especially as you can buy them dirt cheap from Ikea!