Experiencing issues with the LED lights on your thermostat heat link in the UK? A small number of customers have experienced an issue where the LED light on their heat link doesn't light up and they can't control heating or hot water. This only applies to 3rd gen Nest Learning Thermostats. If this is you, we'd like to apologize for the inconvenience and solve this for you as soon as possible. The fastest way to get help is to visit our partner BOXT's booking form. Once you have submitted the form, BOXT will reach out to you within 2-3 days to arrange a service visit to get you up and running again. When filling out the BOXT form, a case number will be pre-populated for you.