Regency® U31 Medium B-Vent Gas Inserts

The Regency Energy U31 is a medium gas insert that vents through a B-vent or a listed gas vent liner. That can make it a good match for some older chimneys, where a different venting approach opens up options.

It uses a hand-lit standing pilot, and the gas control and remote work without electricity, so the fire keeps going during a power outage. The standard 127 cfm variable-speed blower does need power to run. Natural gas input goes up to 30,000 BTU/hr. Whether a B-vent insert makes sense for you comes down to the chimney, so that's where we start.

What Makes the Energy U31 Different

• B-vent option. Vents through a B-vent (4 inch minimum) or a listed gas vent liner, which can suit some older chimneys.
• Works without power. The gas control and remote don't need electricity. Only the blower needs power.
• Blower standard. A 127 cfm variable-speed blower comes with it.

This listing is the U31-10 for natural gas.

Key Specifications

• Natural gas input: Up to 30,000 BTU/hr
• Venting: B-vent, 4 in minimum, or a listed gas vent liner
• Blower: 127 cfm, variable speed, standard
• Steady-state efficiency: 58.45% natural gas

Regency supplies these input and efficiency figures. Your results depend on the chimney, the fireplace, and how the insert is used.

We'll inspect your chimney and measure the fireplace before recommending a B-vent insert. Visit our Auburn, Brunswick, and Yarmouth showrooms to talk it through, or browse more gas inserts.