The answer to 'thermostat not heating' is that there could be several common causes, including a malfunctioning thermostat, issues with the heating system, or problems with the electrical connections. Symptoms may include the thermostat display not working, the heating system not turning on, or the house not reaching the set temperature.
Some potential solutions include checking the thermostat batteries, ensuring the thermostat is properly programmed, and verifying the heating system is receiving power. If the issue persists, it's best to call a professional HVAC technician to diagnose and repair the problem.