Top features include an adjustable thermostat and ventless design, ... The 32-inch-wide natural gas fireplace generates up to 19,100 BTUs of heat to warm rooms up to 700 square feet.

But using a natural gas fireplace can increase your gas bill. ... Jeremy Biswell from Fluesbrothers said technicians may be able to add a thermostat control to some older insert-style gas fireplaces.