BoilerFaultCodesTechnical description
NTC1 open (or not connected) (NTC1 = outlet sensor) Probe manifold not connected
What causes this fault?
This fault occurs when the water inside the boiler reaches an unsafe temperature, triggering a safety switch to prevent damage. The most common reasons are a pump failure that stops water from moving or a blockage in the system causing heat to build up too quickly.
This issue often appears when the heating is first switched on after summer, as pump components can seize up during long periods of inactivity.
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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