Poor all round ....
9Y ago Dyson E S installed a new boiler for my elderly Mother. Two young guys cut corners and did not hide they wanted to get in and out. Leak and other issues resulted in me calling Manager out to inspect who admitted very poor job. Boiler has just broken down, and second major component part is believed to have failed within 9y. Contacted DES and was reminded warranty 2Y and "life expectancy of new boiler 7-10 years only". I forwarded them evidence from the Internet suggesting this was not the case ..... Avoid.