Ideal Boiler L2 Fault Code

Ideal Boiler L2 Fault Code: Causes and Fixes

Last updated on June 10th, 2024

An Ideal L2 fault code means your boiler has locked out because of flame failure. This can happen for many reasons.

I have been repairing boilers full-time for over a decade and an L2 fault on an Ideal Logic boiler is quite a common boiler fix.

What Does L2 Mean on a Boiler?

An L2 fault code is an Ideal boiler fault that means ignition lockout or flame failure.

Gas Supply Fault

The most likely cause of an L2 boiler fault is the boiler has been locked out due to low gas pressure or not getting any gas.

This can be checked quite easily without having to open up the boiler.

Blocked or Frozen Condensate Pipe

Another cause of an L2 fault could be a blocked or frozen condensate pipe.

If it’s freezing cold weather and you have an external condensate pipe, there is a good chance it has frozen.

Faulty Boiler Parts

An L2 boiler fault code could also mean that a part in the boiler is broken and needs to be replaced, but most of the time in my experience it is a gas supply issue.

How to Fix an L2 Fault

To fix the L2 fault on a boiler the first thing I would check is that the gas is turned on at the gas meters emergency control valve (ECV).

How to fix E133 on boiler
Emergency control valve turned on

  • Gas supply fault: If you have other gas appliances, like a gas hob or gas fire, then check to see if these are working to find out if you have a gas supply problem.
  • Prepay gas meter: If you have a prepayment gas meter, then make sure you are in credit, as this is quite a common situation I come across.
  • Frozen condensate pipe: If it’s freezing outside, then having a frozen condensate pipe is possible. You can pour hot water on it to melt the frozen condensate and reset the boiler. 

You will need to call your gas supplier if you are having gas pressure problems like a gas meter blockage.

How to Diagnose L2 Fault

This image is from the Ideal Logic boiler manual fault finding process for a Gas Safe engineer to diagnose an L2 fault.

Faulty Parts on an L2 Fault

A gas supply problem is the most common cause of an Ideal boiler L2 fault code.

Here are some other potential causes:

  • Spark ignitor unit: Might need replacing (most common faulty part on an L2 fault)
  • Faulty gas valve: Might need a new one
  • Worn-out spark electrodes: Might need to be cleaned and straightened or replaced
  • Faulty PCB (printed circuit board): The PCB is the brain of the boiler and might need to be replaced
Ideal ignitor unit replacement YouTube video

How to Reset an Ideal Boiler

The first thing I would check on an Ideal boiler that is not working, no matter what fault code is showing, is to check the pressure and reset the boiler.

Knowing how to reset an Ideal boiler is the simplest way to get your boiler working again as it might have locked out.

how to reset an Ideal boiler
Ideal boiler reset

To reset an Ideal boiler, you must turn the right-hand knob clockwise as far as it will go and hold it there for a few seconds, then release it.

L2 on Boiler Won’t Reset

If your L2 boiler fault won’t reset, this means you have a problem that needs to be fixed before trying to reset it again.

When the ignition has gone to lockout it won’t reset until the cause of the L2 error is fixed.

If you have fixed a gas supply issue and it still won’t reset, this could mean there is air in the gas pipe.

You should try resetting it a few times to get the gas into the boiler and to get rid of the L2 fault code.

Ideal Boiler Guides


Fixing an L2 fault on an Ideal boiler is usually done by fixing a gas supply issue. If you have a prepayment gas meter, make sure you put some money on and reset the boiler.

On a cold winter night, the L2 fault code on a boiler is highly likely to be caused by a frozen condensate pipe. This is easily fixed by pouring hot water over the condensate pipe outside and resetting the boiler.

If you are sure you have gas and the condensate pipe isn’t frozen or blocked, then you should ring a local Gas Safe engineer as it’s probably a part inside the boiler that needs to be replaced.

Feel free to ask me any questions in the comment section below and I’ll try my best to help.

Please share this post if you find it helpful.


Is L2 on a boiler dangerous?

L2 on a boiler is not dangerous as it means your boiler has gone to lockout.


  • Steven Reid

    I am a full-time plumber and Gas Safe registered engineer. I incorporated Housewarm Ltd. in 2011 to provide heating and plumbing services to homes in Newcastle upon Tyne, England. I now blog about what I've learned over the years to help DIYers and plumbers.

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2 thoughts on “Ideal Boiler L2 Fault Code: Causes and Fixes”

  1. Hi Steven,

    I hope you’re well,
    I hope you can help! my meter ran out so my boiler went about a day with gas as I topped it up the following day as it’s prepaid and I work in the office. I now put money on the card and uploaded it but my boiler keeps coming up as L2. I really don’t think there’s anything wrong with the boiler as it was working prior the gas running out.
    Any idea how to fix this ? Any help would be appreciated!

    Thank you,


    1. Hi Enya, sounds like there’s no gas in the gas pipe as the boiler might have sucked it out when trying to light after it ran out. Now the gas is back on it will be sucking in the air until it’s gone from the gas pipe. Try resetting the boiler a few times

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