The answer to 'boiler not working' is that there are several common causes, including a lack of fuel, a malfunctioning thermostat, low water pressure, or a problem with the pilot light or ignition system. Symptoms may include the boiler not turning on, strange noises, or a lack of heat.
For many basic boiler issues, homeowners can try some simple troubleshooting and DIY fixes. However, more complex problems or safety concerns may require calling in a professional HVAC technician. It's important to address boiler issues promptly to prevent further damage or safety hazards.