Hi @Northernlampy ! Let's try to perform a click test and see if this behavior is because of the Heat Link. Therefore, please go by the Heat link with your Nest app device and do the following steps: using the Nest App, make sure the display is black and call for heat, the screen should change into orange and listen for a click from the Heat Link. Then turn off the heating (the screen should turn black) and listen for the "click" sound. Let me know how it went afterwards.