The Simple Fix: What to do When Your Boiler Pilot Light Goes Out

As the nights draw in and you switch your heating on for the winter, nothing is more frustrating than a silent boiler. If your system runs on an older boiler model, a common culprit is a pilot light that has extinguished. While a faulty pilot light can be a simple fix, it’s a critical component—if it goes out, your boiler cannot fire up, leaving you without heat or hot water.

At Brightside Heating, we handle all boiler models across Medway and Maidstone. While modern boilers feature automatic ignition, understanding your pilot light is essential for keeping older, reliable systems running efficiently during the cold months.

Why Does the Pilot Light Go Out?

The pilot light is a small, constant flame that ignites the main gas burner when your thermostat calls for heat. It usually goes out due to one of three common issues:

1. A Draught: A strong gust of wind or air movement near the boiler can simply blow the flame out.

2. A Faulty Thermocouple: This is the most common mechanical reason. The thermocouple is a safety device that senses the heat from the pilot flame. If the flame goes out, the thermocouple shuts off the gas supply to prevent a leak. If the thermocouple is worn or dirty, it might fail to sense the flame, cutting the gas supply even when the flame is lit—or, more commonly, failing to hold the flame at all.

3. A Blocked Pilot Jet: Over time, dirt or soot can block the tiny opening (the pilot jet), reducing the gas supply to the flame until it goes out.

Your Step-by-Step Guide to Relighting the Pilot Light

Always follow the instructions printed inside your boiler’s front panel.

1. Safety First: Before you attempt anything, check to see if you can smell gas. If you can, do not proceed. Turn off the gas supply and call a Gas Safe engineer immediately.

2. Locate the Panel: Open the boiler access panel and find the main burner and the pilot light assembly.

3. Follow the Sequence: There will be a series of buttons or dials (usually marked ‘Pilot,’ ‘Off,’ and ‘On’).

   • Turn the control knob to the ‘Pilot’ setting.

   • Hold down the pilot button, which releases gas to the pilot jet.

   • Press the ignition button (or use a long match/lighter, depending on the model) to spark the flame.

4. Hold and Release: Once the pilot light is lit, keep the pilot button held down for about 30–60 seconds. This allows the thermocouple to heat up and “lock” the flame.

5. Return to ‘On’: Slowly release the pilot button. If the flame remains lit, turn the control knob to the ‘On’ or ‘Run’ setting.

If the flame goes out immediately after you release the button, the problem is almost certainly a faulty thermocouple. This requires a professional replacement.

Don’t let a small flame stop your central heating. If you suspect a deeper issue with your ignition system, our experts are ready to diagnose and repair the problem quickly. Find out more about our services on our Boiler Repairs page.

If your pilot light won’t stay lit, don’t risk a DIY repair on a gas appliance. Our Gas Safe engineers offer fast, reliable Boiler Repairs across the Medway and Kent area.

Call Brightside Heating now to book your repair and restore your heat today.