So, I was considering purchasing a Nest learning thermostat from an online retailer during a promotional period. On the official Nest webpage for Nest approved installers I was pleased to find that, Terry, my regular heating engineer was listed. I contacted Terry by phone, at the time I was also considering Worcester Bosch's own internet based controller. Terry very patiently went through the pros and cons of both devices and helped me arrive at my decision. Terry installed the Nest thermostat when it arrived a few days later. I've been using Terry's services for a few years now, I'm always confident that I'm paying a fair price. He's always very helpful and keen to give useful advice.