Reasons to choose an electric boiler are:
Quieter.
No chimney.
No piping for fuel or fuel tank.
Near 100% energy transfer.
May be eligible for energy credits and rebates.
May be the only approved design in carbon conscious areas.
Less moving parts.
Faster servicing by having fewer parts.
Blowdown can be contained safely with no tank vent.
Meet all ASME and UL standards in the US and Canada.