BoilerFaultCodesYour boiler has lost communication with your wall thermostat, meaning it cannot receive the signal to turn on your heating.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Check the ModuLine room thermostat. If the thermostat functions properly, the control panel is defective. Replace the control panel.
What causes this fault?
This fault occurs when the digital communication link between your wall controller and the boiler's internal computer is broken. The most common reason is a wiring failure at the connections or an internal electronic failure within the ModuLine thermostat itself, which prevents the boiler from receiving the command to fire up.
DIY fix possible
Check if your wall thermostat has run out of batteries and replace them if necessaryEnsure the thermostat is turned up higher than the current room temperatureReset the boiler by turning the control knob to the 'reset' position for five seconds
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