I am really not sure, the oil boiler is on a timer and thermostat so once the temperature has been reached I think the heating will go off. If this is the cause of the hub disconnecting any idea what I could do about this?
The first thing would be to establish if the boiler is the problem. Not a great time of the year to do this but one evening turn the boiler off so that it is not not coming on or being thermostatically controlled.
If you get through the evening without the Smarthub disconnecting it would be fair to suspect that the boiler is causing the problem. To be sure though you would need to do the above a couple of times.
If however the hub still disconnects you will know that it is not the boiler and that it could be some other electrical item that is causing the problem or possibly nothing to do with the electrical circuit in your house.