Hi there - sorry I cant help with your specific request but we too have been visited by Perry Vale Energy Savers and have been very impressed! we had the slightly unlikely plastic liners behind the radiators installed (not very high tech) but more usefully a gadget which tells you how much electricity you are using, so if you turn on the kettle it shoots up, and if you boil the kettle whilst doing some ironing, well boy you had better save up for that one!

All in all we were very pleased. Not often you get something for free these days and the guy who came around was very polite and helpful (and had the largest feet I have ever seen).