4 Green Flashes Low
Your boiler is temporarily struggling to talk to its internal control parts and is trying to reconnect itself.
Technical description: Communication error between printed circuit board (PCB) and Control – this is a temporary error, the system should reset on its own
Typical repair cost: £0-280 (including labour)
DIY fix possible
Wait up to 10 minutes to see if the error clears itself as designedTurn the selector switch to 'Reset' for 5 seconds and then back to its original positionSwitch the main electrical power to the boiler off and back on again
Protect yourself from future repair bills
A boiler cover plan would cover faults like 4 Green Flashes — no call-out fees, no surprises.
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Parts commonly replaced
- Printed Circuit Board (PCB)
- Control Interface
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