BoilerFaultCodesThis light is actually a positive signal showing that your boiler's internal electrical fuse is working correctly and the control board has power.
This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.
Technical description: Lit confirms the fuse is good on PCB 37.
What causes this fault?
This light is not actually a fault, but a status indicator showing that the boiler is receiving electrical power. It confirms that the internal glass fuse is intact and the circuit board is functioning as intended. If your boiler is not working while this light is on, the issue lies with a different component or external control rather than the power supply.
DIY fix possible
No action required as this light indicates a healthy electrical connection to the board.If the boiler is not working despite this light being on, check that your room thermostat is turned up.Ensure the main power switch to the boiler is in the ON position.
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A boiler cover plan would cover faults like LED3 on PCB 37 — no call-out fees, no surprises.
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Ideal Response FF80 is discontinued — time for a new one?
Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
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