What to do when a boiler pilot light is out
Updated on 11th November 2026:
Kieran Haig
Technical Repair Engineer, British Gas
What to do when a boiler pilot light goes out
- If your boiler’s pilot light goes out, your boiler won’t ignite and you’ll be without heating or hot water.
- Lots of things can cause your boiler’s pilot light to go out, from strong draughts to broken parts.
- You might be able to relight your boiler’s pilot light yourself. But if the light repeatedly goes out, you’ll need to contact an engineer.
If your boiler pilot light has gone out and you don’t smell any gas, it could be a simple fix. In this guide, we’ll cover how to safely relight your boiler’s pilot light and when to call an engineer.
What is a pilot light in a boiler?
A pilot light is a steady blue flame that ignites a boiler when you switch the heating or hot water on. They’re typically only found in older models, as most modern boilers now use an electronic spark igniter instead.
What happens when a pilot light goes out?
The pilot light ignites the central burner when heat or hot water is needed. So if the light goes out, your boiler won’t ignite – leaving you without heating or hot water until it’s relit.
Can you relight a boiler’s pilot light yourself?
Yes, you can relight a boiler pilot light yourself provided it’s safe to do so and the boiler manual says you can. The process can vary between models, so always refer to the specific manufacturer instructions for your boiler.
If you’re not sure how to safely relight your boiler’s pilot light, or the pilot light goes out after multiple attempts, call a Gas Safe engineer.
Never relight the pilot light if you smell gas – this is an emergency and should be reported immediately to the National Gas Emergency Service on 0800 111 999.
How to relight a boiler’s pilot light
Here’s a general guide to relighting a boiler’s pilot light. Remember to check the manual for specific instructions for your make and model.
- Find the gas control dial. It’ll have positions for ‘off’ and ‘pilot’.
- Switch the dial off. Then wait 10 minutes for any unburnt gas to disperse.
- Switch the dial to ‘pilot’. Then push the control dial firmly inwards and hold it in place.
- Ignite the flame. Continue to press the dial, then hold down the ignition control until the light ignites. Or use a long lighter to ignite it via the jet opening.
- Hold, then release. Keep holding the control after the flame ignites for 30-60 seconds, then slowly release. If the flame stays lit, switch the dial to ‘on’.
Why does my pilot light keep going out?
There could be lots of things causing your pilot light to keep going out. Here are some of the most common reasons.
A broken thermocouple
A thermocouple is a sensor that detects when the pilot flame is lit. If it’s broken and it doesn’t detect the flame, it could switch the gas off – which could cause the light to go out.
A dirty pilot light orifice
The pilot light orifice is a tiny nozzle inside the pilot assembly that controls the gas flow towards the pilot light. A buildup of dirt on the pilot light orifice can obstruct the flame and stop the pilot light from staying lit.
Problems with your gas regulator
A gas regulator controls gas pressure. If the gas regulator malfunctions or the pressure drops too low, the force of gas reaching the boiler might not be strong enough to maintain a steady flame.
A strong draught
A strong draught could blow the pilot light out. This can happen in homes where the boiler is located near an external door, window or poorly sealed vents. The odds of your pilot light being blown out may also increase in very windy weather.
If this happens frequently, it might be simpler to address the draught before calling an engineer.
Low gas pressure
Low gas pressure can restrict the amount of gas being sent to the flame. This can be caused by a few different reasons, but they’ll all prevent the pilot light from staying lit.
When to call an engineer
If you’re unable to relight your pilot light, or any of the following happens, you’ll need to call a Gas Safe engineer.
- The gas supply doesn’t seem to be working
- The pilot light isn’t staying lit after several attempts to relight it
- Your boiler is over 10 years old and the light repeatedly goes out
- You’re not sure how to reignite the pilot light
If you smell gas, open doors and windows, avoid flames and electrical switches and contact the National Gas Emergency Service immediately on 0800 111 999.
How much does it cost to repair a pilot light?
The cost of repairing a pilot light issue can vary between providers. At British Gas, we offer one-off boiler repairs for a fixed price of £295. This includes everything needed to fix the issue, including all parts and labour and a 12-month guarantee.
Our Gas Safe registered engineers fixed 1.3 million boilers last year – and you don’t need to be an existing British Gas customer to book. Better yet, if we can’t fix your boiler, we won’t charge you a penny. Not even a call-out fee.
Need help?
Broken boiler? Our expert engineers are on hand to help. If you’re without heating or hot water, book before 11am and we’ll be there the same day.
Based on Sept 2025 - Aug 2026 data, 83% of customers who contacted before 11 am received a same-day service.
Frequently asked questions
How to fix a pilot light that keeps going out?
A boiler pilot light that keeps going out shouldn’t be ignored. If your boiler’s pilot light repeatedly goes out, it could signal an underlying problem with your boiler. So it’s important to get it looked at by a Gas Safe registered engineer.
Why would a pilot light go out on its own?
There are lots of reasons why a boiler’s pilot light might go out on its own. Common issues include low gas pressure, draught and ventilation problems, or a broken thermocouple. Some issues could be a simple fix, while others may need to be looked at by a professional.
Should I worry if the pilot light goes out?
If you don’t smell any gas, a pilot light going out isn’t always a serious problem. But if it keeps going out, it could signal an underlying issue that needs fixing by an expert.
If you do smell gas, call the National Gas Emergency Service immediately on 0800 111 999.
Can you still have hot water if the pilot light is out?
No, you won’t have hot water if your boiler’s pilot light is out. The pilot light ignites the central burner when hot water is requested. If the light goes out, your boiler will fail to ignite and you won’t have any hot water until the light is relit.
Do I need to turn the gas off if the pilot light goes out?
No, you don’t normally need to turn the gas off if the pilot light on your boiler goes out. If the flame goes out, the thermocouple should turn off the gas supply automatically.
If you smell gas, switch off the gas supply (if it’s safe to do so) and call the National Gas Emergency Service immediately on 0800 111 999.
How to prevent the pilot light from going out?
Booking a regular boiler service can help prevent issues with your boiler’s pilot light. During your service, a gas engineer will inspect your boiler to make sure everything’s working safely and efficiently. And they’ll also spot any issues that might affect the pilot light in future.