BoilerFaultCodesTechnical description
Domestic hot water sensor NTC fault
What causes this fault?
This fault occurs when the boiler's main control board suffers a hardware failure or a memory error that prevents it from managing the heating safely. The most common reason is electrical fatigue of the small components on the board or a short circuit caused by age. Because the 'brain' of the boiler can no longer process instructions, it shuts the system down to prevent further damage.
This fault can sometimes follow heavy summer thunderstorms, as power surges or nearby lightning strikes are known to damage sensitive electronic circuit boards.
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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