What is the eco-mode setting on a boiler? is it cheaper than the normal function? Our team are fully qualified to help with all aspects of gas and oil fired boiler maintenance, installation and repair. Why use ahp boiler services for all your boiler and central heating needs? Combi my yo mother has just swapped to one and had her immersion removed she can't believe the constant hot water even though we've been telling her for years. Where can i buy.