I would give this company a zero rating if I could. The worse company I've ever had to deal with. Our boiler was installed in September 2017 and exactly a week after that the pressure dropped, I call and was told that this should not be a reoccurring thing as I only had to fill the water about once a year. I was told that if this happens again, i need to call them to send out an engineer as it means there's a leak. This had happened over 10 times since then and I've been on the phone countless times trying to get someone from northern gas to come and have a look at it. This company is a nightmare and I'd stay far away from them. I have been promised countless call backs with never happened, I've had unsympathetically rude staff etc.... wish I had gone somewhere else...!!