What Are Flueless Gas Fires for Fireplaces ? Flueless Gas Fires are a perfect option for someone who Doesn't have a chimney. The Fires are 100% efficient, and operate by cleaning the exhaust from the burner, but with no loss of heat up the chimney! Available in a large Range of types, and Sizes. No Chimney ! No Problem ! Flueless Gas Fires for Fireplaces sit into a mock firpelace fitting situation.