E119/E118 - boiler has detected low pressure
Your boiler has detected that the pressure is too low, so you need to top it up.
It is quite normal for the boiler pressure to need topping up from time to time, and this is something you can easily do yourself, especially as your boiler has an Easy-Fill permanent filling link.
Look underneath the boiler for a green lever. It’s on the right, near the front of the boiler.
Pull the green lever down. You will hear water running into your central heating system.
Watch the pressure gauge on the front of the boiler while you are holding down the green lever.
When the needle in the pressure gauge reaches the top edge of the green triangle around the figure 1, let go of the green lever.