January 2, 2026 – A Nest Thermostat T3017US has been implicated in a series of severe overheating incidents, including one where a home reached a dangerous 110 degrees Fahrenheit. The product reportedly caused a furnace to run nonstop, even when set to cool, leading to significant property damage and raising serious fire safety concerns.
Product Details
Incident Overview
The initial report from a consumer on February 20, 2024, described a persistent issue with their Nest Thermostat T3017US, where the device, operating via Wi-Fi, would cause the furnace to activate unnecessarily. The problem escalated, with the furnace running even when the thermostat was explicitly set to cool. The retailer, Best Buy, replaced the unit after multiple malfunctions were reported. However, the issue persisted.
In April 2025, the retailer advised replacing the control panel, which was done, but it also failed to resolve the problem. The most alarming incident occurred on September 14, 2025, when the homeowner was away. The Nest thermostat reportedly caused the furnace to run continuously for six hours, despite being set to cool at 72 degrees Fahrenheit. Upon their return, the homeowners discovered their upper level had reached a staggering 110 degrees Fahrenheit, while the lower level was 96 degrees. The extreme heat caused their prescription drugs to spoil and require replacement.
The homeowner stated that this was not an isolated incident, noting that “dozens of days” of similar overheating had occurred, often with the furnace running nonstop far exceeding the set temperature. The only way to stop the overheating furnace each time was to manually switch off its power source on the wall. This particular incident on September 14, 2025, occurred even after their four-year-old furnace had been checked and its control board replaced by a licensed professional, indicating the issue stemmed from the thermostat itself.
The homeowner has since turned off the power to the problematic thermostat, had it removed, and replaced it with a mechanical unit, expressing strong conviction that the Nest thermostat is a significant fire hazard. As of the report date, the manufacturer had not yet been contacted by the consumer.
Safety Concerns
The incidents reported with the Nest Thermostat T3017US raise several critical safety concerns:
- Immediate Fire Hazard: Prolonged, uncontrolled heating to temperatures like 110 degrees Fahrenheit within a home, especially while unoccupied, poses a severe risk of house fire. Flammable materials, electrical components, and structural elements can be compromised or ignited under such extreme and sustained heat.
- Property Damage: Beyond the fire risk, extreme internal temperatures can damage a wide range of household items, including electronics, perishable goods, prescription medications (as reported in this incident), plastics, furniture, and even delicate artwork. The cost of replacing such items can be substantial.
- Health and Safety Risks: If occupants, particularly vulnerable individuals such as children, the elderly, or those with health conditions, were present during such severe overheating, they could face risks of heatstroke, dehydration, and other heat-related illnesses. The reported incident of spoiled prescription drugs highlights a direct health impact.
- Energy Waste and Financial Burden: The continuous and unnecessary operation of a furnace, especially over several hours or “dozens of days” as reported, leads to substantial energy waste, resulting in significantly higher utility bills for affected consumers.
- Unreliable Home Climate Control: The primary function of a thermostat is to reliably regulate home temperature. A malfunction that causes extreme overheating completely undermines this function, leaving consumers with no effective control over their indoor climate.
What Consumers Should Do
If you own a Nest Thermostat T3017US or suspect similar issues with any smart thermostat, here are immediate steps and recommendations:
- Monitor Performance Closely: Pay close attention to your heating and cooling system’s behavior. If your furnace or air conditioner runs continuously, especially when it shouldn’t, or if your home’s temperature deviates significantly from the set point, investigate immediately.
- Check for Overheating: Regularly check the temperature in your home, especially during periods when you are away. If you notice unusually high temperatures, particularly when the system is set to cool, take action.
- Immediately Cut Power: If your thermostat is causing uncontrolled heating, the safest immediate action is to turn off the power to your heating system at the circuit breaker or the furnace’s dedicated power switch. Do not rely on the thermostat itself to shut off the system.
- Professional Inspection: Contact a qualified HVAC professional to inspect your entire heating and cooling system, including wiring and the thermostat’s connection. Ensure they are aware of the specific issues you’re experiencing.
- Document Incidents: Keep detailed records of any malfunctions, including dates, times, temperatures reached, duration of the issue, and any steps you took to mitigate it. Photos or videos can be valuable evidence.
- Report the Incident: If you experience similar problems, report the incident immediately to the U.S. Consumer Product Safety Commission (CPSC) at www.SaferProducts.gov. This helps authorities track potential hazards and initiate investigations.
- Contact the Manufacturer: Reach out to Nest Labs, Inc., directly to report your concerns and seek technical support or a resolution.
- Consider Alternatives: If issues persist and you are concerned about safety, consider replacing the smart thermostat with a reliable mechanical or another trusted brand’s model.
Manufacturer’s Response
As of the date of this report, Nest Labs, Inc. has not provided a response to the specific incident described in this report.
Legal Help Available
If you or a loved one has been injured by a defective product or suffered property damage due to a product malfunction, you may be entitled to compensation. The experienced product liability attorneys at Farzan Law understand the complexities of defective product cases and can help you navigate the legal process.
Contact us today for a free consultation: 424-325-3112
Our legal team has successfully represented clients in product liability cases involving defective appliances, automotive defects, medical devices, and consumer products. We work on a contingency fee basis, which means you don’t pay unless we win your case.
Note: This information is based on incident reports provided by the U.S. Consumer Product Safety Commission. If you find information that is incorrect, please contact us immediately so we can correct the post to reflect accurate information.
Disclaimer: The information provided in this post is not intended to be legal or medical advice. This article is based on publicly available incident reports. The incidents mentioned have not necessarily been independently verified or adjudicated.