Your boiler is limiting the temperature of the water being sent to your hot water cylinder, which typically means the water won't get as hot as usual.

Limitation of cylinder charging temperature in celsius

What causes this fault?

This fault occurs when the boiler detects that it cannot safely heat your hot water cylinder to the requested temperature, often due to a conflict between the boiler's settings and the cylinder's actual heat demand. It is typically caused by a faulty temperature sensor or a thermostat that is sending inaccurate data to the boiler's control board.