Looking for book recommendation

Hi - does anyone know of a good book (or website) that clearly explains central heating 'interlock' theory, with particular attention to the wiring of room stat/cylinder stat/programmer/3-port valve/boiler/pump/wiring centre?
I have some books that touch on the subject and I have some manufacturers data sheets for specific items of equipment, but would like an explanation ranging from basic concepts to system fault-finding. Thanks.

"Central Heating Combination Boiler Repairs Fast and Easy: Professional's Pocket Handbook"

"Central Heating Combination Boilers: Fault Finding and Repair "

from amazon

try this book lots of wiring diagrams has come in useful many times, but you need some knowledge of electrics
ISBN: 0-7506-6436-3 http://www.amazon.co.uk/Domestic-Ce...64363/ref=sr_11_1/202-7986221-2479035?ie=UTF8

Also http://content.honeywell.com/uk/homes/systems.htm#C

Thanks very much for your recommendations - that latter book looks particularly interesting, and I do have some knowledge of electrics.