No unknown heat sources near the thermostat. Called HVAC technician,
after complete system check, determined it was faulty Nest. Replaced
with Honeywell unit. All working now. Nest was 9 months old…
Mine did the same thing. Changed batteries, let it cool down.
Reinstalled. Within minutes it was reading a high ambient temp, at least
30 degrees warmer than room temp. Just started last night…
