Updated on 12th December, 2022 by Martin Astley
A pilot light should be a crisp blue color. As you may remember from your high school chemistry classes and your experiments with Bunsen burners, a blue flame is the most energy efficient, as it uses a small amount of gas to produce a lot of heat.
But if your pilot light is yellow, or even if it has a slight yellow or orange tint, then wasted energy may be the least of your concerns. A yellow or orange pilot light will produce carbon monoxide, an odourless and colourless gas that can fill your home and cause carbon monoxide poisoning. Symptoms of this condition include dizziness, headache, fatigue, nausea, unconsciousness, brain damage, and death. If you begin to feel unwell and your pilot light is burning yellow, then seek medical assistance immediately.
Yellow pilot lights mean that the gas-to-air mixture in your gas boiler is incorrect and that too much air is getting into the system. While you don’t necessarily have to make a claim on your boiler cover service contract if your pilot light is yellowish, if you cannot resolve the problem yourself, you should switch off the gas supply to your boiler and call a Gas Safe-registered engineer out to inspect the appliance. We aim to respond to all boiler breakdown claims in as little as four hours and no longer than 24 hours, so there’s no need to panic with 247 Home Rescue!
Carbon monoxide warning signs
As well as a yellow pilot light, other signs that your gas boiler is leaking carbon monoxide include staining or soot around the appliance, condensation within the room or a smoky smell. Switch off the boiler and call out 247 Home Rescue’s boiler breakdown team if you notice these problems.
Check for breezes
A slight breeze could cause extra air to get into your gas supply and cause your pilot light to blow out or burn yellow or orange. This is actually one of the most common reasons for a pilot light to burn yellow and can be resolved by simply draught-proofing your property and ensuring the boiler cover is properly secured. As always, do not block any vents or flues, and do not unscrew the boiler cover or mess around with the mechanics of the boiler if you are not Gas Safe-registered. See our “My Pilot Light Keeps Blowing Out” page for more information.
Adjust the pilot valve
There should be a screw on the pilot light valve that you can turn to adjust the flame. Check the manufacturer’s instructions to locate this screw. Then, simply turn the screw until the flame turns back to the crisp blue colour it is supposed to be. Be careful when doing this and follow safety instructions.
Clean out the pilot tube
If there are no breezes and if adjusting the pilot valve does not turn your yellow pilot light to a blue colour, then you may have to clean out the pilot tube. Dirt and grime can clog up the pilot tube and disrupt the air/gas balance. You may need to contact a Gas Safe-registered engineer for this gas boiler repair, but if you are skilled enough, you can do it yourself with a nail, needle, or other thin object. Be careful when doing so; you don’t want to rupture the pilot tube.
Still having trouble?
Never attempt any boiler repairs if you are not confident in your abilities to do so – many boiler repairs can only be legally conducted by Gas Safe-registered engineers – and remain aware of the dangers of gas and carbon monoxide poisoning. If you haven’t been able to repair your pilot light, then switch off the boiler until an engineer has repaired it for you.
Don’t attempt to touch any part of your boiler or central heating system if you’re unsure. Did you know? It’s illegal for anyone to use a gas appliance if they think it’s unsafe. It’s always better to be safe than sorry as you could make things worse.
Instead, call us on 0345 3192 247 and we can help. Our technical team will run through some simple troubleshooting to see if your problem can be resolved on the phone or they can book one of our friendly and knowledgeable Gas Safe registered engineers to get you back up and running as soon as possible.
247 Home Rescue accepts no liability for any injuries or damages you sustain following the advice on this website. If in doubt, seek professional assistance.