Common Ideal Boiler Error Codes

The complete guide to what each Ideal boiler error code means and how to fix it!

Is your Ideal boiler not working properly and displaying a strange error code on its screen?

Fear not! In this guide, we will be explaining what each Ideal fault code means and how to fix it.

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How to Reset Ideal Boilers

Before we get started, it’s worth noting that many of these Ideal boiler error codes can be resolved by resetting your boiler, so it’s important to know how to reset your model.

Take a look at the table below to find out how to reset your Ideal boiler according to the model.

Ideal Boiler Model	How to Do a Boiler Reset
Ideal Logic	Turn the knob to the ‘reset’ position.
Ideal Logic+	Single press the ‘reset’ button.
Ideal Vogue & Ideal Vogue Max	Turn off the boiler using the On/Off control. Set the heating controls between 30ºC - 80ºC. Turn the boiler back on.
Ideal Mini	Single press the ‘reset’ button.
Ideal Mexico HE	Press and hold the ‘reset’ button for 2 seconds and release.
Ideal Isar	Press and hold the ‘reset’ button for 2 seconds and release.
Ideal Icos	Press and hold the ‘reset’ button for 2 seconds and release.

Now let’s jump into what each boiler error code means and how you can fix it.

Ideal Boiler Fault Codes

F Ideal Fault Codes

Fault Code	Issue	How To Fix
F	The boiler is operating in frost mode.	Frost mode turns on when the water in the system has dropped below a specific temperature to prevent it from freezing. This doesn’t require a fix.
F1	Low water pressure.	Make sure the system water pressure is between 1 and 1.5 bars on the system pressure gauge. Find out how to re-pressurise your boiler here.
F2	Loss of flame.	Check your other gas appliances are working to make sure the gas supply is present in your home. If other appliances aren’t working, ensure your gas supply is turned on at the meter and that any prepaid meters have credit. If it is just your boiler without gas, contact Ideal (if your boiler is still under warranty) or a Gas Safe engineer to come out and take a look.
F3	Fault with fan.	Restart your boiler using the guide above. If the issue with the fan persists, contact Ideal (if your boiler is still under warranty) or a Gas Safe engineer to come out and take a look.
F4	Fault with flow thermistor.	Restart your boiler using the guide above. If the issue with the flow thermistor persists, contact Ideal (if your boiler is still under warranty) or a Gas Safe engineer to come out and take a look.
F5/L5/L9	Fault with return thermistor.	Restart your boiler using the guide above. If the issue with the return thermistor persists, contact Ideal (if your boiler is still under warranty) or a Gas Safe engineer to come out and take a look.
F6	Outside temperature sensor failure.	Restart your boiler using the guide above. If the issue with the outside temperature sensor persists, contact Ideal (if your boiler is still under warranty) or a Gas Safe engineer to come out and take a look.
F7	Low mains voltage.	Contact your electricity provider or a qualified electrician to take a look.
F9	Unconfigured PCB.	Contact Ideal (if your boiler is still under warranty) or a Gas Safe engineer to come out and take a look.
FD	No water flow.	This is an issue caused by the boiler’s installation. This could be resolved by re-pressurising your boiler, but if this doesn’t help you should contact your installer to rectify the problem.
FU	Flow/return differential 50ºC.	Contact Ideal (if your boiler is still under warranty) or a Gas Safe engineer to come out and take a look.

L Ideal Fault Codes

Fault Code	Issue	How To Fix
L1	Flow temperature overheat / No water flow.	Make sure the system water pressure is between 1 and 1.5 bars on the system pressure gauge. Find out how to re-pressurise your boiler here.
L2	Ignition lockout.	Take a look at the condensate pipe and check for any blockages caused by ice or sludge. If it is an ice blockage, simply use a hot water bottle or pour warm (not boiling) water over the pipe itself. If the blockage is caused by sludge, contact Ideal (if your boiler is still under warranty) or a Gas Safe engineer to come out and clean it.
L3/L4	No flow thermistor fault.	Restart your boiler using the guide above. If the issue with the return thermistor persists, contact Ideal (if your boiler is still under warranty) or a Gas Safe engineer to come out and take a look.
L5/F5	Fault with the return thermistor.	Restart your boiler using the guide above. If the issue with the return thermistor persists, contact Ideal (if your boiler is still under warranty) or a Gas Safe engineer to come out and take a look.
L6	Flame detection fault.	Reset your boiler.
LC	There have been 5 boiler rests in 15 minutes.	Turn the electrical supply to the boiler off and then back on. If the issue persists, contact Ideal (if your boiler is still under warranty) or a Gas Safe engineer to come out and take a look.
L-F	Boiler is failing to ignite.	Press the reset button for 2 seconds. The boiler will attempt to ignite again. If it still doesn’t work, check the other gas appliances in your home to see if it is an issue with the mains.
L-A	Boiler overheated.	Make sure your boiler pressure is topped up and bleed any radiators that need bleeding. Then reset your boiler.

C Ideal Fault Codes

Fault Code	Issue	How to Fix
C	The boiler is operating in central heating mode.	This isn’t a fault and doesn’t require a fix.
C0	BCC (boiler chip card) activation fault.	Reset the boiler. If this doesn’t resolve the problem, contact Ideal (if your boiler is still under warranty) or a Gas Safe engineer to come out and take a look.
C2	BCC (boiler chip card) fault.	Reset the boiler. If this doesn’t resolve the problem, contact Ideal (if your boiler is still under warranty) or a Gas Safe engineer to come out and take a look.

Other Ideal Boiler Fault Codes

Fault Code	Issue	How to Fix
H-3	Domestic hot water thermistor error.	Reset the boiler.
0	The boiler is in standby mode.	This isn’t a fault and doesn’t require a fix.
D	The boiler is operating in hot water mode.	This isn’t a fault and doesn’t require a fix.

Other Boiler Fault Codes

Have you got a Viessmann, Worcester Bosch or Alpha boiler and aren’t sure what the fault code means? Don’t worry! We’ve also created guides to the most common codes for all of these brands.

Check them out below:

For more advice and guidance when it comes to your home heating, check out our helpful blogs or get in touch with our friendly team at iHeat today!

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