BoilerFaultCodesYour boiler is working correctly but is currently waiting for a signal from your room thermostat or programmer to tell it to turn the heating on.
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: No Heating demand from external controls 230V
What causes this fault?
This code appears when the boiler is ready to provide heat but hasn't received an electrical signal from your thermostat or timer to do so. The most common cause is that your house is already up to the desired temperature, or your heating programmer is currently in an 'off' period. It can also happen if your thermostat has run out of batteries and can no longer send a signal to the boiler.
DIY fix possible
Check that your room thermostat is turned up higher than the current room temperature.Ensure your heating programmer or app is set to 'On' or 'Auto'.Replace the batteries in your wireless room thermostat if the screen is blank or showing a low battery icon.
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A boiler cover plan would cover faults like S.30 — no call-out fees, no surprises.
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