The answer to 'how long will thermostat last' is that a properly installed and maintained thermostat can typically last 5-10 years. Thermostats are designed to be durable and reliable, but their lifespan can vary depending on factors like the quality of the thermostat, how often it's used, and the environment it's installed in. With proper care and occasional battery replacement, many thermostats can provide comfortable, efficient temperature control for your home for many years.
It's important to regularly check your thermostat to ensure it's functioning correctly. Signs that your thermostat may need to be replaced include inconsistent temperature readings, difficulty programming, or the thermostat simply not responding to changes. If you notice any issues with your thermostat, it's best to have a qualified HVAC technician take a look to determine if it needs repair or replacement.