HUGE boiler savings!

Compare obligation-free quotes now!

  • All boiler models quoted
  • Trusted local boiler engineers
  • Latest March deals

New & Replacement

Save on new boiler installs!

  • Upgrades and new installs
  • Expert advice included
Get Free Quotes

Repairs & Servicing

Boiler maintenance for less!

  • Emergency repair work
  • Annual service savings
Get Free Quotes

Pilot Light Keeps Going Out? Find Out Why

If your boiler pilot light keeps going out you’re not alone. This is a common problem that most UK homeowners experience at some point. It can be frustrating and can lead to bigger issues if not addressed quickly. Fortunately understanding why your boiler pilot light keeps going out is the first step to resolving the problem. In this article we’ll discuss some of the most common causes of this issue and offer some tips for getting your boiler back up and running.

Definition of Boiler Pilot Light

Your boiler pilot light is a small flame that is used to ignite the main burner on a boiler. This flame is kept lit at all times to ensure that the boiler can be used when needed. The pilot light is typically located in the control panel of the boiler and is lit manually. You can normally see it through a small viewing window on the front cover of your boiler. It is important to check the pilot light regularly to ensure that it is lit and that the boiler is functioning properly. If the pilot light goes out it can prevent the boiler from operating.

Common Causes of Boiler Pilot Light Going Out

  1. Thermocouple Malfunction: The thermocouple is a small metal device that detects heat from the pilot light flame and helps control the flow of gas to the main burner. If the thermocouple is not working properly it can cause the pilot light to go out.
  2. Air in Gas Line: If air gets into the gas line it can cause the pilot light to go out as the gas flow is disrupted.
  3. Blocked Gas Line: Dirt and debris can accumulate in the gas line and block the flow of gas to the pilot light which can snuff the flame.
  4. Loose Pilot Assembly: If the pilot assembly is loose or not properly connected it can cause the pilot light to go out.
  5. Poor Ventilation: Boilers require good ventilation to function properly. If the boiler is in a poorly ventilated area the pilot can struggle to stay lit.
  6. Faulty Gas Valve: If the gas valve is faulty you may experience an issue keeping the flame lit.

Dirty Boiler Sensor

The most common cause for a failed to ignite or extinguished pilot light is due to dirt build-up on the flame sensor which prevents it from detecting that there is an existing flame present in the combustion chamber. To fix this issue an engineer may turn off power supply at mains switch then use cotton buds dipped into white spirit/alcohol solution (not flammable liquids) cleaning all parts inside and outside of gas valve where necessary then re-igniting.

Faulty Thermocouple

A faulty thermocouple may also prevent your boiler from lighting its pilot because it won't sense when heat needs to be generated within the combustion chamber meaning no energy will flow through its connection. This can lead to total failure until replaced or repaired properly by qualified service engineer.

Low Gas Pressure

Another potential cause for your problem could be low gas pressure coming into the appliance which prevents sufficient fuel being supplied during ignition process thus resulting in the extinguishing of the flame. An engineer will check the regulator setting first and adjust accordingly if needed.

Blockages In Ventilation System

One more possible reason why your pilot keeps going out might have something do with blockages caused either internally such blocked air vents near burners themselves, or externally such as clogged chimney flues.You should therefore always make sure these areas are cleaned regularly in order to maintain safe working conditions especially during the Winter months when demand is highest

Professional Repairs

If you have attempted to re-light your boiler pilot light several times and it continues to go out it is important that you call a professional repair service. A qualified technician will be able to identify the root cause of the problem and provide an appropriate solution.

In many cases attempting DIY repairs can make matters worse as incorrect parts may be used which could damage your boiler further, invalidate warranties and more importantly present a significant risk to health. Therefore we advise calling in an experienced heating engineer who can diagnose and fix any underlying issues correctly with minimal disruption.

Need a new boiler?


New installations


Upgrades / replacement


Start Saving!

Boiler faulty?


All repair work


Regular servicing


Get some quotes!

News Discover the latest boiler offers this March, get some free quotes!