No. A gas fireplace is not one of the eligible items of non-business energy efficient property, even if it is used as the home's main heating source. Review the instructions for form 5695.
https://www.irs.gov/pub/irs-pdf/i5695.pdf
Qualifying property is:
• An electric heat pump water heater that yields a Uniform Energy Factor of at least 2.2 in the standard Department of Energy test procedure.
• An electric heat pump that achieves the highest efficiency tier established by the Consortium for Energy Efficiency (CEE) as in effect on January 1, 2009.
• A central air conditioner that achieves the highest efficiency tier that has been established by the CEE as in effect on January 1, 2009.
• A natural gas, propane, or oil water heater that has a Uniform Energy Factor of at least 0.82 or a thermal efficiency of at least 90%.
• A stove that uses the burning of biomass fuel to heat your home or heat water for your home that has a thermal efficiency rating of at least 75%.
•a natural gas, propane, or oil furnace or hot water boiler that achieves an annual fuel utilization rate of at least 95.
•an advanced main air circulating fan used in a natural gas, propane, or oil furnace that has an annual electricity use of no more than 2% of the total annual energy use of the furnace (as determined in the standard Department of Energy test procedures).
