Stay away... far away... After couple of weeks after installation we had a leak from new pipes. Of course Northern Gas did not have anyone to sent out so we were told just to wait. By the time they came out 2 weeks later the ceiling was dry but bulging, but anyway guys said the leak has sealed itself so it's fine and off they went. Not even a year after the installation another massive leak from pipes going to the boiler. Trying to get someone from Northern Gas to come and have a look at their poor work is like winning a lottery! No chance! So I was left with no heating, no water and no lights because of the leak in cold at end of November. After spending all day on the phone to them the only thing they could offer was Vaillant service the next day and one of their plumbers in 2 weeks time. Mind I had to switch off the water as it was pouring down from the ceiling, tripping my lights and at that point no heating. Freezing cold and 2 kids at home. In the end I asked them what to do and thoughtfully someone said to get a plumber and they will reimburse the costs. Next day both Vaillant service engender and independent plumber looked at pipes installed by Northern Gas and said they have used Old pipes that had pin holes in them not even year after installation!!! Northern Gas agreed to pay for damages to ceilings, drying of the house and cost of plumber. No communication and No sign of Money till this date!!! But I'm left with damaged ceilings, pipework that may still break at any time and uncertainty. Not worth the money. Broken promises. Do not trust them.