Ideal Boiler L2 Fault Code

Ideal Boiler L2 Fault Code: The Most Likely Causes and Fixes

Last updated on September 23rd, 2023

An Ideal boiler 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.

Here I’ll show you some of the most common causes of an L2 fault on an Ideal boiler and how to fix.

What Does L2 Mean on a Boiler?

An L2 fault code on an Ideal boiler fault 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.

Ideal Boiler L2 Fault Code How to Fix

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.

How to fix L2 fault on Ideal boiler
How to fix L2 fault on Ideal boiler

Faulty Parts on an L2 Fault Code

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 leave feedback or ask me any questions in the comment section below and I’ll try my best to help.

Please share this post if you found it helpful.

Ideal Boiler L2 Fault FAQs

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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