My Nest totally ignores the schedule, never turns heating on in the morning. Also imposes a minimum value of 16.5C irrespective of the value I set. Does respond to my Android app, so not a router connection problem. Any ideas of how to fix please?
If you haven’t already sorted this, try resetting the heat link box and your thermostat. Mine did this after my boiler’s annual service last year and when I was connected to a new gas mains and it was all because heat link was switched off for more than an hour. Also if you’ve had a wifi outage or power cut (even a small one) it can cause thermostat to lose track of wifi and do its own thing. To reset heat link box press and hold the big button in the middle for twenty seconds or so until it quickly flashes green and orange and release; to reset thermostat press and hold until it turns off and then release. I hope that helps. If not it may be a valve in your heating system.