Technical description
Normal pressure, system warm/hot. O.K.
What causes this fault?
This is not a fault, but rather a status reading showing the current water pressure within your central heating system. The numbers indicate that the internal pump is active and the water has expanded slightly as it heats up, which is exactly how the system is designed to function. As long as the display remains in this range while the heating is on, your boiler is operating perfectly.
You may notice these readings more frequently during winter when the heating is running constantly and the system water remains hot.
DIY fix possible
This fault may be fixable without an engineer. Check your manual first.