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There are no modifications you can make specifically to the boiler to effect the auto reset you want. The only viable alternative short of taking preventative measures to mitigate possible freeze damage ( I can spell those out if you like) would be to install a back up generator with an auto transfer switch that switches over the power from the grid to the generator in the event of an outage. There are also battery back up systems that serve a similar purpose.
Actually a reset is performed by turning the power off to the boiler waiting a few minutes then turning it back on again. In almost every instance if there is a call for heat the boiler will respond when the power comes back on