What Causes Pilot Lights to Keep Going Out? January 13, 2026 When your boiler’s pilot light keeps going out, it can quickly turn into a stressful situation. Not only does it leave you without heating or hot water, but it can also signal a deeper issue within your boiler system. While modern boilers no longer rely on a pilot light, many older models still do, and understanding why it keeps extinguishing is key to keeping your heating system running safely and efficiently. If you’re experiencing repeated pilot light problems, it’s always best to seek help from qualified heating engineers who can diagnose and resolve the issue safely. Common Causes of a Pilot Light Going Out There are several reasons your pilot light might keep going out. Some are minor and can be resolved easily, while others may point to more serious problems that require expert attention. 1. Faulty or Misaligned Thermocouple The thermocouple is a safety device designed to detect whether the pilot light is burning. If the flame goes out, the thermocouple automatically shuts off the gas supply to prevent leaks. However, if it’s worn, bent, or covered in soot, it can mistakenly sense that the flame has gone out even when it’s still burning. This will cause the gas valve to close, cutting off the flame. In many cases, a simple realignment or replacement by a professional can solve this problem. 2. Blocked Pilot Orifice Over time, dust, carbon deposits, or other debris can clog the pilot orifice – the small opening where gas escapes to maintain the flame. When this becomes partially blocked, it can cause the flame to become weak, unstable, or to go out entirely. Cleaning the orifice requires care and should only be performed by a qualified boiler repair specialist to avoid damaging delicate components. 3. Inconsistent Gas Supply An unreliable gas supply is another common culprit. This could be caused by low gas pressure, a partially closed valve, or issues with the gas line. If you notice that your pilot light goes out at random intervals or struggles to relight, it might be due to fluctuating gas levels. This situation requires urgent attention from a Gas Safe registered engineer, as it could indicate a safety issue with your gas supply. 4. Problems with the Gas Valve The gas valve regulates the amount of gas that flows to your pilot light and burners. If it becomes stuck, corroded, or starts to fail, it can intermittently cut off the gas, causing the flame to go out. A faulty gas valve is a more serious issue that must be inspected and replaced by an experienced heating engineer in Chesterfield. 5. Draughts and Ventilation Issues Sometimes, the reason can be as simple as a draught. Boilers installed in garages, lofts, or near exterior doors can be exposed to strong airflow that blows out the pilot flame. It’s also important to maintain adequate ventilation to allow safe gas combustion. If your pilot light keeps going out during windy weather, a draught may be the cause, and repositioning or protecting the boiler area might help. What You Can Safely Check Before Calling an Engineer If your pilot light goes out, there are a few simple checks you can carry out before calling a professional: Ensure there is no strong draught blowing towards your boiler. Check that your gas supply is still active and other appliances are working. If it’s safe and your boiler manual allows, try relighting the pilot light following the manufacturer’s instructions. However, if the pilot light repeatedly goes out after relighting, it’s best not to keep trying. This could signal a fault that requires expert diagnosis and repair to avoid gas leaks or further damage. Preventing Future Pilot Light Problems The best way to avoid persistent pilot light issues is to keep your boiler well maintained. Regular servicing by a qualified engineer will include cleaning the pilot assembly, checking the thermocouple, and testing gas pressure to ensure everything is functioning as it should. An annual service not only prevents inconvenient breakdowns but also helps your boiler operate more efficiently and safely. Reliable Boiler Repairs and Servicing in Chesterfield If your pilot light keeps going out or you suspect an issue with your heating system, M Spencer Plumbing & Heating Ltd can help. Our team of Gas Safe registered experts provides professional boiler repairs in Chesterfield, ensuring safe, long-lasting solutions for your home. Whether it’s a faulty thermocouple, blocked orifice, or gas supply issue, our heating engineers in Chesterfield can quickly identify the cause and get your heating back up and running. Call M Spencer Plumbing & Heating Ltd today or fill out our contact form to arrange a repair or book your annual boiler service.
