BoilerFaultCodesYour boiler has detected that the water pressure is too low or your water isn't moving through the system properly to operate safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Insufficient water pressure or poor flow in system. Check pressure gauge reading; if low restore pressure (see 2.2.1) then reset as described in code 01. If the pressure gauge reading is correct check for sufficient primary water movement or correct operation of flow switch. Reset as described for code 01.
What causes this fault?
This fault occurs when the boiler detects there isn't enough water volume or pressure to safely transfer heat away from the burner. The most common reason is a simple leak or air in the radiators causing the pressure to drop, but it can also happen if the internal pump fails to move the water around. Without this constant flow, the boiler shuts down to prevent the internal components from overheating.
This issue often appears in autumn when the heating is turned back on for the first time, as small leaks over the summer can gradually drain the system's pressure.
DIY fix possible
Check the pressure gauge on the front of the boiler; it should be between 1 and 1.5 bar.If the pressure is low, use the filling loop valves under the boiler to top it up until the needle reaches 1.2 bar.Turn the mode selector switch to the 'OFF/RESET' position and then back to 'ON' to clear the fault.
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