Ideal F9 or L9 Fault Code: PCB Fault
Hertfordshire, Bedfordshire & Cambridgeshire
F9, or L9 on some displays, is a PCB fault on an Ideal boiler. The control board has detected a problem with itself.
Worth one power cycle in case it is transient. If it returns, it needs an engineer and quite possibly a board.
What F9 or L9 actually means
The PCB runs everything: ignition, the fan, the pump, the diverter valve, and every sensor input. When it reports a fault in itself, the boiler stops.
It is a broad code by nature, because a board can fail in many ways.
What you can safely check yourself
One power cycle. Repeatedly power cycling a board with a genuine fault does not help and can make an intermittent problem harder to pin down.
Turn the power off at the switch, wait a minute, and turn it back on. If the boiler runs normally afterwards it may have been a one off.
If F9 returns, stop there.
When to stop, and why
If it comes back after one power cycle, leave it and call an engineer.
What causes it beyond the simple checks
A failed control board, water ingress onto the board, damaged wiring or connectors giving the board bad inputs, or a supply problem. The wiring and connections get checked before a board is condemned, because a poor connection is a lot cheaper to fix.
How Vantage can help
We are Gas Safe registered under 956889 and cover Hertfordshire, Bedfordshire and Cambridgeshire, with an emergency line answered 24 hours a day. Call us on 01462 506374. See also boiler repair and boiler servicing.
Frequently asked questions
Does F9 always mean a new board?
No. Damaged wiring, water ingress or a poor connector can produce it, and those get checked first.
Is it worth replacing a PCB on an old boiler?
That depends on the age and condition of the appliance. We will give you the repair price and an honest view on whether it is worth spending.
Is F9 dangerous?
It is not a combustion fault. The boiler has stopped itself, which is the safe outcome.
Related fault codes
Other Ideal codes: L1 · L2 · LC · L6 · F1 · F2 · F3 · F4 · F5 · F6 · F7 · F8 · all boiler advice. See also boiler repair. See also how long does a boiler last.
In Ideal’s own words
The Ideal installation and servicing guide lists F9 or L9 as: PCB Fault
Ideal use different code sets across their ranges and generations. The definition above comes from The Ideal installation and servicing guide. If your boiler is a different model and the code behaves differently, check the manual for your appliance or ring us and we will tell you what it means on your unit.
When to call an engineer
If the checks above have not cleared it, the next steps are engineer work and the boiler should not be reset repeatedly in the meantime. Call Vantage Plumbing and Heating on 01462 506374. We are Gas Safe registered under 956889, the line is answered by a person at any hour of any day, and you get a price before anyone starts.
Need help today?
Call and speak to a person, any hour, any day of the year. Get a fixed price quote or call 01462 506374.
Need help today?
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Vantage Plumbing and Heating covers Hertfordshire, Bedfordshire and the surrounding areas. Call and talk to an engineer, or send us the details and we will come back to you with a price.
Gas Safe registered, number 956889. Emergency line answered 24/7.