Restart the boiler: Press and hold the restart button for a minimum of five seconds, then release. Do not try to do more than five restarts in 15 minutes or less because you will see an LC code.
If this does not fix the problem, please speak to Ideal Heating on 01482 498660 or use the live chat option to talk to one of our representatives. Please quote Fault Code F5 because a Gas Safe registered engineer will want to visit the property.
You can find more information on fault codes in the boiler user guides. They are available in paper copy, or pdf from our website: https://idealheating.com/user-guides.