BoilerFaultCodesTechnical description
Maximum setting of heater control knob
What causes this fault?
This code appears when the physical central heating temperature dial on the boiler's control panel has been turned to its maximum position. It is not an internal component failure, but rather the boiler confirming that it is operating at its highest possible heat output. This often happens if someone has bumped the dial or adjusted it manually to try and heat the home faster during a cold spell.
This is more common during the winter months when homeowners increase their thermostat settings or adjust the boiler dial to deal with freezing outdoor temperatures.
DIY fix possible
Locate the heating control knob on the front of the boiler panelTurn the knob slightly to the left to reduce the temperature set-pointCheck if the display returns to the standard pressure or temperature reading