Worcester Boiler Reset Guide

Resetting a Worcester Bosch boiler can resolve temporary lockouts caused by minor interruptions such as power cuts, pressure drops or ignition timing errors. However, a reset is not a repair. Used incorrectly or repeatedly, it can mask serious faults and create safety risks.

This reset guide is designed for homeowners, landlords and property managers who want clear, model-specific instructions on how to reset a Worcester boiler safely and when to stop and call an engineer.

Safety first: A Worcester boiler should only be reset once. If the fault recurs, the boiler requires inspection by a Gas Safe-registered engineer.

A reset is appropriate only when the boiler has entered a temporary lockout due to a non-critical interruption.

You may reset your boiler if:

• There has been a brief power cut (FD fault)
• Gas supply was momentarily interrupted
• System pressure dropped slightly, but is now corrected
• The boiler failed to ignite once (EA fault – first occurrence only)

Do not reset if:

• The boiler repeatedly locks out
• You see flame-related faults (FA, F7)
• The boiler has overheated (E9, 224V)
• There is a burning smell, a water leak or an unusual noise

Most Worcester Greenstar boilers use a dedicated reset button or a mode selector dial.

Standard Reset Method

1. Locate the reset button (often marked with a flame or “RESET”)
2. Press and hold for 3–5 seconds
3. Release and wait for the boiler to restart
4. Allow up to 60 seconds for ignition

If the boiler does not restart or the fault code reappears, do not attempt another reset.

Greenstar i / Si / CDi Classic (Combi & System)

• The reset button is located on the front control panel
• Press once only

Common reset-eligible faults: FD, EA (single occurrence), C7

• Use the reset icon on the digital display
• Ensure system pressure is 1.2–1.5 bar before resetting
• Reset is allowed only once for faults like 227V

• Use the front reset button
• Software-related errors (224) must not be repeatedly reset
• Manufacturer-level diagnostics may be required

• Reset via the reset button or power cycle
• Interpret light signals carefully:
  • Fast flash = lockout
  • Slow flash = overheating or ignition issue
• Reset once only

A reset will not repair mechanical or safety-critical faults, including:

• Fan failures (C6, C7 recurring)
• Gas valve faults (FA, F7)
• PCB or control module errors (A8, 9U, CC)
• Pump failures or circulation problems (A1, D4)

If the boiler resets but fails again, the issue is confirmed as active, not temporary.

• ❌ Resetting multiple times in a short period
• ❌ Resetting after overheating faults
• ❌ Ignoring recurring flame or ignition errors
• ❌ Using reset as a substitute for servicing

Repeated resets can damage components and invalidate warranties.

You should stop immediately and arrange professional help if:

• The same fault returns after a reset
• The boiler shows EA, FA, F7, E9, 224V
• Pressure keeps dropping
• The boiler shuts down during operation
• You manage a rented property (landlord compliance)

A Worcester boiler is designed to lock out to protect occupants and property. Resetting correctly helps distinguish between a temporary interruption and a genuine system fault, preventing unnecessary damage and unsafe operation.

If your Worcester boiler fails to restart or the fault code returns, professional diagnosis is required.

Worcester Care provides specialist Worcester Bosch boiler support, including:

• Fault diagnosis
• Safe repairs
• Manufacturer-aligned servicing
• Landlord and homeowner support

📞 Book an engineer with us.