BoilerFaultCodesYour boiler is failing to stay lit after you try to start it because the pilot light is going out as soon as you let go of the ignition button.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Main burner fails to light and pilot is extinguished when pressure on the control knob is released. Control knob not held down long enough.
What causes this fault?
This fault occurs when the safety system, centered around a part called a thermocouple, fails to detect a stable flame. When you release the ignition button, the boiler shuts off gas flow because it incorrectly believes the pilot light has gone out, or the components responsible for holding the gas valve open have physically worn out. The most common reason is a deteriorated thermocouple tip that can no longer generate the tiny electrical pulse needed to keep the boiler running.
This issue is frequently seen during the first cold spell of autumn when the boiler is switched back on after being idle throughout the summer.
DIY fix possible
Locate the gas control knob on the boiler.Follow the lighting instructions on the boiler casing, ensuring you press the control knob in fully.Hold the control knob down for at least 20 to 30 seconds after the pilot flame appears before slowly releasing it.
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