Ideal Boiler Fault Codes

Ideal Boilers is a UK-based company providing innovative and high-quality heating solutions for over 100 years. The company is committed to providing reliable and efficient heating systems that are designed to meet the specific needs of homeowners and businesses.
Ideal Boilers has a wide range of products, from combi boilers to system boilers designed to suit different heating requirements. The company’s products are known for their high efficiency, easy installation, and low maintenance, making them a popular choice for residential and commercial customers.
Ideal Boilers is also committed to sustainability and reducing carbon emissions. The company has introduced a range of energy-efficient boilers designed to reduce energy consumption and carbon emissions, helping to create a more sustainable future.
ideal boilers

Ideal Boiler Fault Codes

FD: Lack of water flow

Due to installation errors, this problem may originate from air locks in your system, a faulty pump or wiring. It could also be due to insufficient water in your central heating system or poor water circulation. The resolution The issue is not with your boiler but with its installation. You may fix the problem by repressurising your boiler, but if it persists, it is best to contact your installer to inspect your heating system and rectify the issue.

F1: Insufficient water pressure

The problem If your heating system does not have enough water, this fault may occur due to low pressure. Using the built-in filling loop, you can fix this problem by topping up your boiler's water pressure to 1.5. If you still face issues, contact a Gas Safe registered engineer.

F2: Flame outage

The problem This usually indicates a flame loss during operation, which may be due to various system errors such as incorrect gas pressure, a faulty gas valve, an issue with your flue, incorrect valve adjustment, or a fan malfunction. The solution Firstly, check other gas appliances and try resetting your boiler. This fault typically occurs in older and low-efficiency boilers, so consider installing a new boiler.

F3: Fan malfunction

The problem This fault is caused by a damaged or loose fan, which could be related to deeper issues such as 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 requires the help of a qualified engineer as it can stem from various causes, and costs can vary.

F4: Flow thermistor malfunction

The problem The F4 fault code often indicates a problem with your boiler's flow thermistor or its operation, typically related to circulation issues. The solution This fault requires a call-out to a Gas Safe registered engineer.

F5: Return thermistor malfunction

The problem This fault refers to a problem with the return thermistor or its operation, often related to a faulty NTC return thermistor, a damaged connection, a temperature differential that is too high between the flow/return thermistors, or a faulty printed circuit board. The solution This fault requires a call-out to a Gas Safe registered engineer.

F6: Outside sensor malfunction

The problem This fault code usually indicates a broken or faulty outside sensor, which could also be related to your boiler's printed circuit board, typically a more expensive fix. The solution If you recently had a weather compensator fitted, the fault may be related to its installation. If you still need one, call a qualified engineer.

F7: Low mains voltage

The problem If you see this fault code, there may be an issue with your property's mains electricity source. For safety, your boiler stops functioning once it detects this fault. The solution The voltage to the boiler has dropped below 190 vol. This is not a boiler fault, but it is best to contact your installer.

F9: Printed circuit board (PCB) malfunction

The problem The F9 fault code on your Ideal boiler usually relates to an unconfigured printed circuit board (PCB). Repairing this fault may be costly, so installing a new boiler is worth it.

L1: Insufficient water flow

The issue: Your boiler takes resistance readings sent to the printed circuit board. If the temperature reading is too high or low, the boiler will stop working as a safety precaution and display a fault code. The solution Try resetting your boiler. If something else is needed, contact a qualified engineer. Overheating is often a problem with older, less efficient boilers, so investing in a new heating system may be worth investing in.

L2: Ignition lockout

The problem Your boiler has 'locked out' as a safety precaution, and the cause needs to be identified. The solution is to Reset your boiler. If you hear rumbling from the system, it indicates a blocked condensate pipe or an issue with your flue, requiring a qualified engineer's call-out.

L3: Flow thermistor malfunction

The problem This fault code typically indicates that someone 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 may indicate that the temperature on your resistance reading is too high. The solution Check your system's pressure reading and bleed your radiators. If the issue persists, we recommend contacting a Gas Safe registered engineer, as the overheating may be due to a deeper problem with your boiler's pump or dry fire stat. .

LF: Ignition fault

The problem Your boiler may have 'locked out' as a safety precaution, and the cause needs to be addressed. Check that other gas appliances in your home are working, and then reset your boiler. If your boiler rumbles, there may be a blockage in your condensate pipe. Contact a qualified engineer to resolve the issue.

L5: Return pipe problem

The problem could happen if someone reset the boiler five times in 15 minutes. The solution Turn off the boiler's power at the fuse spur and then turn it back on. If the issue persists, contact a qualified engineer.

L6: Flame detection malfunction

The problem usually occurs when your flame ignites before your gas. The solution is to Reset your boiler. If the boiler fails to operate and is still covered by your warranty, contact your manufacturer for assistance.

C2: Boiler chip card malfunction

The issue The boiler chip card has an internal error or an activation fault. The resolution Try resetting your boiler. If this does not help, contact a Gas Safe registered engineer.

C0: Central heating signal problem

The issue If your domestic hot water is still functioning, your boiler could be going into pump overrun due to poor heating circulation. Alternatively, your thermostat's signal may be cutting in and out. To rectify this issue, we recommend seeking the help of a qualified engineer to check your room thermostat and radiator circulation.

No display

The issue There is a problem with your printed circuit board. The resolution Turn off the power at the fuse spur and turn it back on. If this does not work, contact our repairs team for assistance. If you have recently had electrical work done on the system, get your installer first.

Noisy operation

Issues such as kettling are common with central heating systems. A humming or rattling noise may indicate loose components or high pressure. To solve this issue, check the system for loose components or try repressurising your boiler. If these measures do not work, contact our repairs team.

Noisy ignition

The issue This may indicate a problem with your system's condensate pipe, gas, or flue. The resolution We recommend seeking the help of a Gas Safe registered engineer.

No/poor hot water

The issue If your heating is functioning, but your hot water is not being delivered as usual, it is typically not a boiler fault. The resolution We recommend seeking the help of a Gas Safe registered engineer. No/poor central heating The issue If your DHW is okay, this is typically not a boiler fault but a problem with your radiators. If there is no central heating issue, contact our repairs team. This fault could be expensive, and installing a new boiler could prove effective.

High gas bill

The issue This could be due to the efficiency rating of your boiler, and your energy bill may also be impacted by how you use your heating. The resolution Check your boiler's efficiency label. Investing in a new A-rated heating system could be beneficial.

Pressure loss

The issue This usually means that water is escaping somewhere in the system, or the problem could be due to the expansion valve failing and causing damage to the pressure release valve. The resolution First, follow our guide on how to repressurise your boiler. If this becomes an ongoing issue, check for leaks. If none are found, get in touch with our repairs team.

Are you interested in replacing your boiler and avoiding recurrent Ideal Boiler Fault Codes and problems?

As a reliable and experienced plumbing and heating service provider, XBG Plumbing & Heating has a team of dedicated professionals who are committed to consistently providing high-quality services to our clients. 

Don’t let plumbing or heating problems cause stress and inconvenience in your life. Trust the experts at XBG Plumbing & Heating to provide you with the solutions you need. Contact us today to schedule a consultation or request a quote!

Ideal Boiler Fault Codes

Does my boiler need to be replaced?

We believe in an transparent and honest approach with all our customers, so will always give you the best advice if your boiler needs replacing. There can be a variety of different reasons that will help identify that your boiler may need replacing. The pilot on your pilot light should burn blue, in the event that’s it’s a different colour, then please call us right away.

Additionally, if you notice strange noises from either the boiler or radiators. You may suddenly hear an increase in noise level, this indicates a problem and needs attention by a qualified gas engineer. Finally, and just as important as the other points, any evidence of any leaks or strange smells coming from your boiler, should be treated as urgent. Please call us 01903 536 502, so we can advise you on the next steps.

Boiler Types Explained

combi boiler installation

Combi boiler

A combination or ‘combi’ boiler is both a high efficiency water heater and a central heating boiler in a single compact unit. Combi boilers heat water directly from the mains when you turn on a tap, so you won’t need a hot water storage cylinder or a cold water storage tank in the roof space.

They are also very cost-effective and energy-efficient as water is heated instantly rather than being heated and then stored in a cylinder. An added benefit is that hot water is delivered at mains pressure, which means that you could get a powerful shower without the need for a separate pump.

system boiler installation

System boiler

System boilers require a cylinder for storing hot water, however the major heating and hot water system components are built into the boiler itself, making it quicker and easier to install. In addition, there is no need for a tank in the loft, so it can be an option in a home with little or no loft space or where the space is earmarked for a conversion.

These boilers are also compatible with solar water heating systems, which deliver environmental benefits as well as lower energy bills.

regular boiler installation

Regular boiler

Regular boilers (sometimes known as traditional, conventional or heat only boilers) are ideally suited to homes that already have a traditional heating and hot water system which is linked to a separate hot water cylinder. These boilers also need a cold water storage tank in the loft to feed the hot water cylinder as well as a tank that maintains the water level of the central heating system.

A regular boiler may be the best option for replacing an existing boiler if the property has an older radiator system, as it might not be able to cope with the higher water pressure that is delivered by system or combi boilers