If your furnace isn't turning on despite the thermostat being set, it could be due to several factors, including power supply issues, thermostat malfunctions, or even problems with the furnace itself. Understanding the components involved, such as the ignition system and safety switches, is crucial for effective troubleshooting. Regular maintenance can also play a significant role in preventing such issues. Curious about what steps to take next? Ask Improvi.ai for personalized guidance.