Worcester Bosch Fault Codes

Welcome to the fault-codes section of this site. The following table or page contains the information required to help repair and diagnose the fault codes being shown on the boiler display. You may be guided through the fault finding sequence or steps, for rectifying your boiler with this fault code. Suggested repair solutions may be provided by a link to a repair page. NB Some fault codes are only applicable to a specific range of boilers only.

Display CodeRepairDescriptionRemedyResources
A1LinkPump has run dry or pump has stalled/seized.Check for water leaks.
Free the pump or replace.
A7LinkHot water NTC sensor defective.Check hot water NTC sensor and connecting lead for circuit breaks/short circuits.
A8LinkBreak in communication to TD200 or/and RT10.Check electrical connections.
b1LinkCode plug not detected.Insert code plug correctly, test and replace if necessary.
C6LinkFan speed too low.Check fan lead and connector, and fan; replace as necessary.
E2LinkCH flow NTC sensor defective.
Check CH flow NTC sensor and connecting lead.
E9LinkSafety temp. limiter in CH flow has tripped.Check system pressure, check safety temp. limiters, check pump operation, check fuse on pcb, bleed appli- ance.
EALinkFlame not detected.Is gas cock turned on? Check gas supply pressure, power supply, igniter electrode and lead, ionisation sensing electrode and lead, flue duct and C02 level.
F0LinkInternal error.Check electrical connector contacts, programmer inter- face module ignition leads are not loose; replace pcb if necessary.
F7LinkFlame detected even though appliance switched off.Check electrode assembly, dry pcb. Flue clear?
FALinkFlame detected after gas shut off.Check gas valve and wiring to gas valve. Clean conden- sation trap and check electrode assembly. Flue clear?
FdLinkReset button pressed by mistake.Press reset button again.
-¦¦- and XXLinkSiphon fill modeWait approx 15 mins

Disclaimer: Information on this website is provided for informational purpose therefore we cannot accept liability for subsequent problems. All repair tasks should be carried out by qualified trades people. We may also receive commission payments when you are taken to external websites and complete purchases from third party sellers, once you leave our site, we cannot be held liable for your purchases.