So whether you have a gas fire that needs servicing, old boiler that needs repairing, or in need of a new, a-rated condensing boiler- then we are here to go the extra mile for you and your family! Clean, efficient and got job done in a timely manner. Kurt did an amazing job! kind and considerate! So, % of the time, there’s no need to turn off the mains water. What is the eco-mode setting on a boiler? is it cheaper than the normal function? A.