Your boiler's main control panel is having trouble talking to the internal computer, which is preventing the system from starting up.

Communication error between fascia and control box – check cables

What causes this fault?

This fault occurs when the digital signals sent between the boiler's front display panel and the main internal computer are interrupted. The most common reason is a loose or damaged connection cable, though it can also happen if moisture gets behind the casing or if one of the electronic circuit boards has suffered a hardware failure.