Gas appliance not working?

We're proud to distribute gas to your home or business, but unfortunately there can sometimes be problems.

Faulty appliance flowchartWe are here to help if there is a gas emergency, such as:

  • a gas leak, 
  • you suspect carbon monoxide is being released, or
  • a loss of gas pressure.

In the event of a gas emergency, we act promptly to make sure the supply to your property or business is made safe and secure again.

There are other experts (gas safe engineers), who can help if your problem is not a gas emergency, such as a boiler fault or a frozen condensate pipe.

If your gas appliance (boiler, cooker or other appliance) is not working as it should, there could be a number of different reasons why. This flow chart can help you diagnose this (click to view a large version).

During the winter, many people experience problems with their boiler due to frozen condensate pipes.  If you have followed the flowchart and the guidance below and believe you have a frozen condensate, you can check if it is  blocked or frozen and try to de-frost it or call a gas safe engineer to help you.

Frozen condensate?

When gas is burned in a boiler, it produces Carbon Dioxide and water vapour. The water vapour exits the boiler via the flue – it's the plume you see from it on a cold day.

The moisture in the flue gas forms water droplets on the inside of the flue – this liquid is known as “condensate”. Modern “condensing” boilers are designed to collect this water and discharge it via a condensate pipe.

To check if your boiler has a condensate pipe, look underneath the boiler at the pipes connected to it. If one of these pipes is plastic (usually white and around 20mm wide) and the rest are metal then it's almost certainly a condensate pipe.

The pipe can be tracked to the outside of the property – the pipe will always run to a drain.

In freezing temperatures, the water in this pipe may freeze and can cause the boiler to operate strangely or sometimes not at all

Symptoms of a frozen or blocked condensate pipe

Long periods of sub-zero external temperatures can mean that a frozen condensate is more likely.  A blocked or frozen pipe may cause;
  • a “gurgle / bubbling” noise from within boiler/flue when trying to light
  • a Fault Code to be displayed on the boiler (varies with manufacturer – see table below)
  • ice visible from condensate pipe outside
  • water dripping from plastic condensate pipe at connection to boiler.

There's lots of advice available on what to do with a frozen condensate - pouring warm water on the external pipe, or wrapping a warm, wet towel on it are two common methods used for thawing. 

If you are not comfortable trying these methods, then contact a Gas Safe engineer to assist you. 

If you are unsure of the cause of your gas appliance not working and think it may be a gas emergency, then call us on 0800 111 999 immediately.

Common boiler manufacturer fault codes

Boiler make Possible fault codes Link to information
Worcester Bosch EA  Help
Ideal F2 or L2 Help
Baxi E133 and E28 Help
Valliant F28 or F29 Help
Glow-worm F1, F4, F28 or F29 Help
Veissman EE or F4  
Vokera 92, 93, or 95 Help

Useful numbers

Some helpful numbers to call if you are experiencing issues with your gas appliances:

For a Gas safe registered engineer in your area call 0800 408 5500 or find an engineer.

If you have home care cover with your gas supplier please contact them directly.

  • British Gas: 0800 294 9650
  • Eon: 0345 303 3040
  • NPower: 0800 0733000

For electricity issues dial 105.