BoilerFaultCodesWhat the manual says
Manufacturer manualMixer M2 regulates to a flow temperature of 20 °C.
What causes this fault?
This fault occurs when the boiler's main brain loses its connection with the electronic module that controls your underfloor heating or second radiator zone. It is usually caused by a loose wiring connection or a component failure within the external control box that manages that specific heating circuit.
This issue often comes to light during the first cold spell of autumn when homeowners try to turn on a secondary heating zone that has been inactive all summer.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Avoid the next call-out bill
A cover plan would handle faults like bA: no call-out fees, no surprise bills.
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