My heating system operates on gas or electric. Is it possible to use both simultaneously?

Yes. The electric heater is usually rated at 1 or 2kw of electrical power, and the gas heater is rated at approximately 6kw. By using both at the same time, an input of 7 or 8kw will decrease the warm up time. Once up to temperature, either the gas or the electricity can be turned off and the system operated in the most economic way.