BoilerFaultCodesWhat the manual says
Manufacturer manualNo heat demand: Controller. Room thermostat blocks heating mode.
What causes this fault?
This status occurs when the boiler is ready to provide heat but is waiting for a signal from your external controls, such as your wall thermostat or timer. The most common reason is that the room temperature is already higher than your set target or the timer is currently in an 'off' period. It essentially means the boiler is 'listening' for a command to start that hasn't been sent yet.
This is very common in the spring and autumn when warmer outdoor temperatures mean your home stays above the thermostat's set point for longer.
DIY fix possible
Check that your room thermostat is turned up higher than the current room temperature.Ensure your heating programmer or timer is set to 'ON' or 'AUTO'.Replace the batteries in your wireless thermostat if the screen is blank or showing a low battery symbol.
Avoid the next call-out bill
A cover plan would handle faults like S.30: no call-out fees, no surprise bills.
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