BoilerFaultCodesTechnical description
Flow and/or return NTC fault | Flow and/or return NTC is defective (tolerances too big)
What causes this fault?
This fault occurs when the boiler's internal computer notices that the two sensors monitoring water temperature are reporting figures that don't match up logically. The most common reason is that one of these sensors has become faulty or uncalibrated, but it can also be triggered if the wiring connecting them to the main control board has been damaged or loosened.
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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