The answer to 'furnace not heating' is that there could be several common causes, such as a faulty thermostat, a dirty air filter, or issues with the furnace itself. Symptoms may include the furnace not turning on, the air not getting warm, or inconsistent heating throughout the home. Solutions can range from simple DIY fixes like replacing the air filter to more complex repairs that require a professional HVAC technician.
If the furnace is not turning on at all, the first step is to check the thermostat settings and replace the batteries if needed. You can also try resetting the circuit breaker or checking the furnace's power switch. If those simple steps don't work, the issue may be with the furnace's ignition system, blower motor, or other internal components that require professional diagnosis and repair.