A Boiler Controller Has Stopped Communicating

Problem

A Boiler Controller is not communicating with the Heat Genius Hub

Boiler controller issues are due to the fact that the Genius Hub cannot route messages to the Boiler Controller.

Check the following to determine the cause of the issue:

Is the boiler controller powered on?
The Boiler Controller is often wired into the same electrical circuit as the boiler. It may be the case that it is not however.
Check that power is available, by looking at the lights on the front.
A single channel controller will have a solid red or a solid green light on it (picture). A dual channel controller will have a solid amber light (picture).
If there are not lights at all, then power must be restored to the boiler controller. You can check the fused spur that feeds the boiler, and also check the
Has a Smart Plug been moved or switched off?
If the Boiler Controller is far enough away from the Hub, Smart Plugs are required to bridge communications between the two. Therefore the Smart Plugs must remain plugged in and in the original location that they were installed.
Has the Genius Hub moved?
If the Genius Hub has moved position then a communications route that has previously been established may no longer be valid. Move the Hub back or add additional Smart Plugs to the system
Have any large objects been moved or added to the home?
Large metallic objects such as desks, fridges, freezers, TV's etc can block a signal path that was previously established. Relocate Smart Plugs, or add additional Smart Plugs to the system.