BoilerFaultCodesTechnical description
Central heating NTC not connected to pipe
What causes this fault?
This fault occurs when the main temperature sensor responsible for monitoring the central heating water loses physical contact with the copper pipe it is designed to sit on. The most common reason is that the metal clip holding the sensor has weakened over time or been knocked loose, preventing the boiler from accurately measuring the water temperature. In some cases, the internal wiring has frayed or become disconnected, breaking the signal between the sensor and the main control board.
This fault often appears at the start of autumn when the heating system is first turned back on after summer, as the sudden vibration and thermal expansion in the pipes can cause a loose sensor to finally shift out of position.
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.