Kozy Heat Nordik 34

It's rated to warm about 1,000–2,000 sq ft. It runs at up to 40,000 BTU/h on either fuel and turns down to 20,000 BTU/h on natural gas or 21,000 on propane. Kozy Heat lists its EnerGuide P.4 efficiency at 70.29% on natural gas and 69.53% on propane.

Your existing opening needs to be at least 23-3/4 inches high, 34-1/8 inches wide at the front, 24-1/8 inches wide at the back, and 16-3/8 inches deep. It's approved for masonry and factory-built wood-burning fireplaces, and smoke shelves, baffles, or firebrick may be removed to reach those minimums, but the fireplace's sheet metal can't be cut. If the metal floor of a factory-built fireplace is removed, the insert sits on the #RT34-FLP floor protector kit, which adds 1/2 inch to the required height. The manual also approves it for bedroom installs.

It's a direct-vent insert that runs two 3-inch flexible pipes (3x3 co-linear) up the existing chimney to an approved cap, such as Kozy Heat's #816 expandable 3-inch pipe with the #816-CAP. The chimney must be at least 6 x 8 inches inside for masonry or 7 inches for a factory-built chimney, and 10 to 40 feet tall. Where the chimney no longer runs through the roof, an approved 4 x 6-5/8-inch co-linear to co-axial adapter can be used, and the insert can't share a flue with any other appliance.

Yes, as long as the backup batteries are fresh. The control module holds four AA batteries (not included) that keep the burner and flame-height adjustment working when the power goes out, but the fan and lights won't run on battery. For everyday use, the insert needs a 120-volt, 6-amp supply that stays live at all times with no switch on it.

It comes with a full-function Proflame 2 remote, and a wall-mount transmitter is an option. The remote can run the insert as a room thermostat or in a smart thermostat mode that lowers the flame as the room nears your set temperature. It also controls six flame levels, six fan speeds, the top light's brightness, and the ember-bed light.

Yes, but it's built for natural gas, so propane takes a conversion kit (LCK-NK34-S in the parts list) installed to the kit's instructions. The option list marks the propane valve step motor as required for propane, and the manual says to finish the conversion before the logs, firebox panels, and light-kit parts go in. On propane the maximum input stays at 40,000 BTU/h.

The fan, top light, and ember-bed light come with the insert, but the screen front and the shroud are both required and ordered separately. The logs (a 7-piece traditional or birch set) and the firebox panels are separate choices too. Fronts come in black, antique copper, black prairie, or vintage bronze arched mission, and the shroud comes in 27 x 40, 30 x 44, or 33 x 46 inches, or as a blank shroud.

An optional 3/4-inch trim can start 6-1/2 inches above the top of the insert, and a combustible 9-inch-deep mantel can start 10 inches above it, getting 1 inch deeper for every inch higher; a non-combustible mantel up to 6 inches deep can start 6 inches above it. The manual also calls for 4 inches to an adjacent sidewall, 1-1/2 inches to a combustible mantel leg, and at least 55 inches from the fireplace floor to the ceiling. It doesn't list clearances for a TV, so check any TV plan with your installer.

A qualified service person should inspect it before use and at least once a year, cleaning the firebox, fan, and burner and checking the pilot and the vent system. You can clean the glass yourself once it's cool, using a fireplace glass cleaner and a soft cloth, never an abrasive cleaner. The fan's bearings are sealed and need no oiling, and the backup and remote batteries need replacing when the low-battery warnings appear.