BoilerFaultCodesTechnical description
Flow/return temperature sensor
What causes this fault?
This fault occurs when the boiler's control board notices that the two sensors measuring water temperature are giving conflicting readings or have failed completely. The most common reason is that one of these sensors has developed a fault or become unclipped, meaning the boiler can no longer safely monitor how hot the water is getting.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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