Heating & Plumbing Doctors on Instagram: "Boiler not working properly with the flame going out 🔥 and repeated flame failure on a Worcester Bosch boiler ⚠️. On testing, gas pressure dropped to 1 mbar when the boiler fired 📉. The gas valve was removed 🛠️ and found restricted with copper oxide debris 🧪 — a black powder formed when copper reacts with moisture and gas impurities over time. I used a Milwaukee 18-volt hoover 🧹 to suck the debris out and the blower function 💨 to push it through, d