NHTSA owner complaints about this part run furthest above the usual seasonal share in November: about 43% more of them name an incident that month than complaints about any part would predict. A complaint is a report, not a measured failure.
What it shows: November is the largest at 10% (all: 7%), followed by January at 10% (all: 9%); the smallest shown is June at 6% (all: 9%).
Data and chart by CalcScrape: Thermostat Replacement Cost Calculator