A cooktop appliance and method of operation is provided. The cooktop appliance may include a user interface, a power source, a burner, a thyristor, and a relay switch. The power source may be operably connected to the user interface. The burner may include a first radiant heat element and a second radiant heat element electrically coupled in parallel to the power source. The thyristor may be operably connected to the user interface and electrically coupled in series between the power source and the first radiant heat element to control activation of the first radiant heat element. The relay switch may be operably connected to the user interface and electrically coupled in series between the power source and the second radiant heat element to control activation of the second radiant heat element.