I would not have chosen a phone charger - the phone could have been fully charged. Alternatively the timer on your off peak meter could have been out of sync. Or maybe it was all a dream
Better to have chosen a portable lamp and got up a bit earlier or plug your heater back into the socket and see what happens overnight.
After all we know the heater works - there appears to be power coming to the socket albeit for a short while. It could still have been your now changed 20amp switch that was causing the problem.
Have you had a search on the internet for the instructions for your meter or contact your meter supply they should send you one. Most econ7 meters have a boost or override button just incase you get a very cold snap. It might save you having to get up early or stay up late.
Better to have chosen a portable lamp and got up a bit earlier or plug your heater back into the socket and see what happens overnight.
After all we know the heater works - there appears to be power coming to the socket albeit for a short while. It could still have been your now changed 20amp switch that was causing the problem.
Have you had a search on the internet for the instructions for your meter or contact your meter supply they should send you one. Most econ7 meters have a boost or override button just incase you get a very cold snap. It might save you having to get up early or stay up late.