Glow Green are genuinely the worst company I have ever dealt with. On the day of installation, the engineer did not show up and the company could not locate him. The boiler arrived late, in any case, and was left on the road outside of my house. After 18 months, numerous engineers, many no-shows, endless phone calls and a complete lack of communication within the company, I still do not have a correctly installed and working boiler. I have had two winters without heating or hot water and they are taking me to court for non-payment, despite assuring me this would not happen. Even their own workforce criticise the company. Avoid.