OpenTherm is a cool idea but even new installations aren't always wired for it. When installing a new smart thermostat I found the installation has been wired a

OpenTherm is a cool idea but even new installations aren't always wired for it. When installing a new smart thermostat I found the installation has been wired as S Plan with the few cables running between the boiler location and valves location already consumed. Makes the job much bigger if you're not prepared for it.