Appalling customer service and would not have given them 1 star if this option were available. Bought a Vaillant boiler in 2017 with a 7 year warranty, this we have in writing. 5 years down the line it's broken but Northern Gas say as its under warranty Vaillant need to fix it. Vaillant say it only has a 2 year warranty. So whilst these 2 incompetent useless companies fight amongst themselves like little school children, we their customer, are left to live in the cold. Neither one of these companies cares about their customers because if they did one of them would have fixed the boiler whilst they fought their battle. We know we are not the only ones in this situation. DO NOT use this company for anything, go else where if you like dealing with an honest and reliable company, because Northern Gas are most definitely not.