Worcester Bosch Boiler Fd Error Code

Reset button pressed or power cut during a fault on Worcester Bosch boilers.

Worcester Bosch All Worcester Bosch boiler codes

Easy DIY fix

On older Greenstar CDi models, Fd means the reset button was pressed when there was nothing to reset, usually by accident. Worcester's engineer booklet adds that a reset button stuck in or a faulty PCB can produce it.

Compatible models

Greenstar CDi Classic ErP combis (29, 34, 38 and 42), CDi Classic system and regular boilers and the HighFlow 440CDi and 550CDi ErP; GB162 V2 commercial boilers use Fd231.

Also shown as

On Worcester GB162 V2 commercial boilers the code reads Fd231, which means the power dropped out briefly while a fault was active.

Difficulty

Most people can clear this one at home with simple checks.

How to fix
When to call a pro
Parts
FAQ

Not sure you are reading the code right? See how to read Worcester Bosch boiler codes.

Safety first: never take the casing off a gas boiler. If you smell gas, open windows, don't use light switches, turn the gas off at the meter if you can and call your gas emergency number from outside. A carbon monoxide alarm going off means the same: switch the boiler off, get fresh air and call.

How to fix Worcester Bosch Fd

Press reset properly
Hold the reset button for about 3 seconds, as the CDi user manuals describe. The flashing lights should stop and the boiler goes back to following the timer and thermostat.
Check the button isn't jammed
If the code comes straight back, look at whether the reset button sits flush or looks stuck in. Don't prise anything off the fascia.

When to call a technician

Fd that won't clear, or returns without anyone touching the boiler, means the button or the control board needs an engineer.

Parts linked to Fd

These are the parts an engineer usually checks for this code. They sit inside the sealed casing, so leave them to a Gas Safe registered engineer.

PCB (main control board)

Frequently asked questions

Which Worcester Bosch models show the Fd code?

Greenstar CDi Classic ErP combis (29, 34, 38 and 42), CDi Classic system and regular boilers and the HighFlow 440CDi and 550CDi ErP; GB162 V2 commercial boilers use Fd231.

Can I fix Worcester Bosch Fd myself?

Usually, yes. Most Fd problems clear with simple checks you can do at home. Start with the first step above: press reset properly.

Other Worcester Bosch boiler codes

Last reviewed 2026-10-21. Codes and steps can vary by model; check your owner's manual.

Sources we checked