This is very handy guide to plumbing but it's not a 'complete guide' to central heating. If you're tackling a central heating installation you'll need other reference sources as well (good luck on finding the latest information on installing a full combi system!). The contents are well laid out and illustrated, they are also repeated page for page as a chapter in the hard backed "Collins Complete Guide to DIY". If you're only interested in plumbing (and basic heating) buy this book. If you're a general DIY-er spend the extra tenner on the Complete Guide to DIY - you won't regret it.