BoilerFaultCodesTechnical description
A problem exists with the primary thermistor.
What causes this fault?
This fault occurs when the internal sensor responsible for monitoring water temperature fails or loses its connection to the main control board. The most common reason is that the sensor has simply worn out over time or the electrical pins have become corroded, preventing the boiler from knowing if the water is getting too hot. Because the boiler can no longer monitor safety temperatures, it shuts down to prevent any internal damage.
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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