Under no circumstances should you use Northern gas heating.Keep well away.Cowboys pure and simple.The after sales service at the Wolverhampton branch is simply appalling.We were left without heating for days.We had over 12 months of warranty left on the product so they didn’t want to know.The customer service department is run by the John Wayne of the cowboy troupe a man so devoid of responsibility it makes me sick.I was finally asked to solve the issue myself.Advice was being given by a phone operator who was reading the instructions from a book!!! DO NOT TOUCH THIS COMPANY WITH A BARGEPOLE.