BoilerFaultCodesTechnical description
Water level low Temperature range too wide | Cause: Pump obstructed, pump running at lower capacity, Air in appliance, system pressure too low, flow and backflow NTC reversed
What causes this fault?
This fault occurs when the boiler detects a massive temperature difference between the water going out to your radiators and the water coming back, suggesting the heat isn't moving. The most common reasons are that the system doesn't have enough water pressure to move or there is a large pocket of air trapped inside the internal pump. In some cases, the pump itself has reached the end of its life and can no longer push the water around your home effectively.
This fault often appears in autumn when the heating is turned on for the first time after summer, as pump components can seize 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.