Your boiler is currently waiting for the digital control system to finish communicating, which usually means it is temporarily busy rather than broken.

Digital regulator status

What causes this fault?

This code appears when the boiler's internal computer is trying to pair or exchange data with smart thermostats or external plug-in controls. It occurs because there is a brief delay or 'handshake' process happening between the boiler and the digital programmer. Most of the time, this is simply a temporary status message rather than a permanent hardware failure.