Are there any downfalls to combi boilers? If you need a central heating engineer or emergency plumber in london. Thank you for the clear and practical advice it’s saved me stress, time and money! A new energy-efficient boiler could save you hundreds off your heating bill every year. The whole experience at clever energy was a smooth one, from my first dealings on the phone, right through to the installation we pretty much saw a saving in our heating bills straight away. I would have.