Had a solar panel instalation and the wiring was left in a dangerous state, even their own trouble shooter said it was dangerous. After three years I needed a new boiler and salesman came, I didnt know he was from Northern Gas. When he told me I said no to his deal to which he replied that he would make sure my solar problems would be guaranteed to be put right. They came to fit my boiler and during the fitting they removed tiling and plaster work, their aim is to do every job as quickly as possible. Some of the problems were corrected and the boiler is very good but the instalation looks aweful. The Wi-Fi thermostat just has a mind of its own and I have to keep setting the temperature manually. Despite numerous phone calls they just ignore my requests and needless to say the problems with my solar panels have yet to be put right. If you want good workmanship and after sales service, DO NO USE Northern Gas Heating.