BoilerFaultCodesTechnical description
Flow and return sensor anomaly detected. The sensor shows an incorrect temperature value.
What causes this fault?
This fault occurs when the boiler's internal computer receives contradictory information from the sensors that monitor water temperature. It usually happens because one of the sensors has failed or developed a electrical 'drift', meaning it is reporting a temperature that is physically impossible or vastly different from its partner sensor. To prevent the unit from overheating or operating unsafely, the system shuts down until the faulty component is replaced.
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.
Find a Gas Safe engineer
Search the official register →