Worcester Bosch FA Fault Code: Flame Detected After Shutdown
Hertfordshire, Bedfordshire & Cambridgeshire
FA on a Worcester Bosch means that after the appliance switched off, a flame was still being detected.
This is one of the codes to take seriously. Turn the boiler off and get an engineer to it rather than resetting and carrying on.
What FA actually means
When the boiler shuts down, the gas valve should close and the flame should go out. The flame sensing electrode should then report no flame.
If it still reports a flame, the boiler cannot tell whether there genuinely is one, which would mean gas reaching the burner when it has not been asked for, or whether the sensing circuit is giving a false signal. It treats both as serious and locks out.
What you can safely check yourself
Do not sit and reset this repeatedly. If the cause is a gas valve not shutting fully, resetting is the wrong response.
Nothing. There is no homeowner check that helps with FA and the components involved are inside the appliance.
Turn the boiler off at the switch and call a Gas Safe engineer.
When to stop, and why
Stop now. Turn it off and ring an engineer.
What causes it beyond the simple checks
The service booklet has the engineer check the condensate trap for blockage first, then inspect the electrode assembly for burn-out and wear, then look at the flue. Beyond that, a gas valve that is not closing fully. A burnt or contaminated electrode giving a false flame signal is the most common finding, but it cannot be assumed, which is exactly why this one is treated as engineer work.
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
Can I use my boiler with FA showing?
No. Turn it off and call a Gas Safe engineer.
Is FA dangerous?
The lockout is the boiler being safe. The reason it locked out is a fault that needs diagnosing rather than clearing.
Is it usually just the electrode?
Often, yes. But the alternative explanation involves the gas valve, and that is not something to assume your way past.
Related fault codes
Other Worcester Bosch codes: F7 · EA · E9 · all Worcester Bosch codes. The same fault on other makes: Vaillant F27. See also boiler repair.
In Worcester Bosch’s own words
The Greenstar CDi Classic engineer’s service booklet lists FA as: After appliance switches off flame is detected.
Worcester Bosch use different code sets across their ranges and generations. The definition above is taken from the Greenstar CDi Classic service booklet. 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.
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