Should a fault develop with your Ideal boiler (or the system), it will enter a safety lock-out mode, and show a fault code which describes the problem with your boiler. Find your fault code, and how to fix it, below.
Ideal logic boiler fault codes
If your Ideal boiler is experiencing issues, it will let you know by displaying a fault code on the front display. Take a look below at what each code means and what you can do to get your Ideal boiler up and running again:
F fault codes:
L fault codes:
L1
L2
L3
L9/ H9/ HA/ LA
LF
L5
L6
C fault codes:
Other faults:
No display
Noisy operation
Noisy ignition
No/poor hot water
No/poor central heating
High gas bill
Pressure loss
FD: No water flow
The problem
This fault could stem from issues with your system’s air locks, pump or wiring due to the fault during installation. This could also be caused by a lack of water in your central heating system or an issue with water circulation.
The solution
This isn’t an issue with your boiler but with its installation. You could try to solve this fault by repressurising your boiler, however, if this doesn’t help we recommend you call your installer to inspect your heating system and rectify the issue.
F1: Low water pressure
The problem
If your heating system doesn’t have enough water, this fault can occur as its pressure could become low.
The solution
It is usually possible for you to fix this issue yourself by topping up your boiler’s water pressure to 1.5 using the in-built in filling loop. If you’re still facing issues, contact a Gas Safe registered engineer.
F2: Flame loss
The problem
This usually means that there has been a flame loss during operation. This issue could be caused by deeper system errors such as incorrect gas pressure, an issue with your flue, a faulty gas valve, an incorrect adjustment of a valve or a fan fault.
The solution
Firstly, check other gas appliances and you could try to reset your boiler. This fault typically occurs with older boilers and low-efficiency systems, so it may be worth considering getting a new boiler installed.
F3: Fault with fan
The problem
This fault is caused by a loose or damaged fan. This issue could be related to deeper problems such as loose or damaged connections, water damage from a boiler leak, a fault with the air pressure switch or a problem with the printed circuit board.
The solution
This fault will require the help of a qualified engineer. As the issue can stem from a range of different causes, costs can vary.
F4: Thermistor fault
The problem
The F4 fault code tends to signify a problem with your boiler’s flow thermistor or an issue with its operation. The fault will typically be related to circulation issues.
The solution
This fault will require a call-out to a Gas Safe registered engineer.
F5: Return thermistor fault
The problem
This refers to a fault in the return thermistor or its operation. related to a faulty NTC return thermistor, a damaged connection, a differential in temperature that’s too high between the flow/return thermistors, or a faulty printed circuit board.
The solution
This fault will require a call out to a Gas Safe registered engineer.
F6: Outside sensor fault
The problem
This fault code will usually show if your system’s outside sensor is broken or faulty. This can also be related to your boiler’s printed circuit board, which is typically more expensive to fix.
The solution
Recently had a weather compensator fitted? This fault could be related to its installation. If your weather compensator wasn’t installed recently, or if you don’t have one at all, call a qualified engineer.
F7: Low mains voltage
The problem
If you notice this fault code, there could be an issue with your property’s mains electricity source. As a safety precaution, your boiler is built to cease operations once it identifies this fault.
The solution
The voltage to the boiler has dropped below 190 vol. This is not a boiler fault but we recommend you contact your installer.
F9: Printed circuit board (PCB) fault
The problem
The F9 fault code on your Ideal boiler typically relates to an unconfigured printed circuit board (PCB).
The solution
Repairing this fault could be a costly expense. It may be worth considering getting a brand-new boiler installed.
L1: Lack of water flow
The problem
Your boiler takes resistance readings which are then sent to the printed circuit board and if the temperature reading is too low or too high, the boiler will cease to work as a safety precaution and display a fault code.
The solution
Reset your boiler. If this doesn’t help, you should then contact a qualified engineer. Overheating is generally an issue that happens with older, less efficient boilers, so it may be worth investing in a new heating system.
L2: Ignition lockout
The problem
Your boiler has ‘locked out’ as a safety precaution. The cause behind this will need to be identified.
The solution
Reset your boiler. If there’s rumbling coming from the system, this suggests your condensate pipe is blocked or that there is an issue with your flue. This requires a call out from a qualified engineer.
L3: No flow thermistor fault
The problem
This fault code typically indicates that someone has changed the printed circuit board (PCB) and used the wrong boiler chip card (BCC).
The solution
This requires a call out from a qualified engineer.
L9/H9/HA/LA: Overheating
The problem
Like L1, this code could indicate that the temperature on your resistance reading is too high.
The solution
Check your system’s pressure reading, you could also bleed your radiators to see if this helps. If not, we recommend contacting a Gas Safe registered engineer as the overheating could be a result of a deeper issue with your boiler’s pump or dry fire stat.
LF: Ignition fault
The problem
Your boiler may have ‘locked out’ as a safety precaution. The cause of this will need to be addressed.
The solution
Check that other gas appliances in your home are working, if so, we recommend that you then reset your boiler. If your boiler is rumbling, there could be a blockage in your condensate pipe. Contact a qualified engineer to fix the issue.
L5: Problem with the boiler return pipe
The problem
This could occur if someone resets the boiler 5 times in 15 minutes.
The solution
Turn off the boiler’s power at the fuse spur, then turn it back on again. If the issue continues, contact a qualified engineer.
L6: Flame detection fault
The problem
This usually happens when your flame comes on before your gas.
The solution
Reset your boiler. If the boiler still fails to operate and your system is still covered by your warranty, you could contact your manufacturer for assistance.
C2: Fault with boiler chip card
The problem
The boiler chip card has an internal error or an activation fault.
The solution
Try resetting your boiler. If this doesn’t help, contact a Gas Safe registered engineer.
C0: Central heating signal issue
The problem
If your domestic hot-water is still working, your boiler could be going into pump overrun due to poor heating circulation. Alternatively, your thermostats signal could be cutting in and out.
The solution
To help rectify this issue, we recommend you seek the help of a qualified engineer to check your room thermostat and your radiator circulation.
Other Ideal boiler faults
No display
The problem
There is an issue with your printed circuit board.
The solution
Turn the power off at the fuse spur and turn it back on again. If this fails, contact our repairs team for assistance. If you’ve recently had electrical work completed on the system, it may be best to contact your installer first.
Noisy operation
The problem
Issues such as kettling tend to be common issues with central heating systems. A humming or rattling noise could indicate issues such as loose components or high pressure.
The solution
To help solve this issue, you could check the system for loose components or try repressurising your boiler. If these measures do not help, contact our repairs team.
Noisy ignition
The problem
This could indicate a problem with your system’s condensate pipe, gas or flue.
The solution
We recommend seeking the help of a Gas Safe registered engineer.
No/ poor hot water
The problem
If your heating is working but your hot water is not being delivered as usual, it typically won’t be a fault with the boiler.
The solution
We recommend seeking the help of a Gas Safe registered engineer.
No/ poor central heating
The problem
If your hot water is working, then this is not typically a fault with the boiler, but instead a problem with your radiators.
The solution
If poor or no central heating is an issue then contact our repairs team. This fault could be expensive to fix, but getting a new boiler installed could prove to be effective.
High gas bill
The problem
This could be due to the efficiency rating of your boiler, your energy bill could also be impacted by the way in which you are using your heating.
The solution
Check your boiler’s efficiency label. It could be beneficial for you to invest in a new A-rated heating system.
Pressure loss
The problem
This usually means that water is escaping somewhere in the system, or alternatively the issue could be due to the expansion valve failing and thus causing damage to the pressure release valve.
The solution
Firstly follow our guide on how to repressurise your boiler. If this becomes a continuous issue then check for leaks, if none are found, get in touch with our repairs team.
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