- Check that the water pressure to the boiler is at 1 to 1.5 BAR.
- Check that the yellow gas isolation valve under the boiler hasn't been turned off. If it is on, the handle/knob will be in pointing in the direction of the pipe
- Turn the boiler off and bleed/let out the air of your radiatiors. Ensure the boiler pressur is still at 1 to 1.5 BAR and turn the boiler back on
- Press the reset button
- If this does not fix the problem, please contact us quoting error code L3
View our video on how to top up your boiler pressure: