Kozy Heat Chaska 335S

It's sized for roughly 900–1,800 sq ft. The manual rates it at 36,000 BTU/h maximum and 22,000 minimum on natural gas, and 36,500 maximum and 24,000 minimum on propane. The brochure lists its EnerGuide P.4 efficiency at 65.74% on natural gas and 66.63% on propane.

Yes. It uses a millivolt gas valve with a standing pilot you light by hand with a push-button igniter, and the manual says the valve doesn't need household current to operate. The fan does run on household power, so during an outage the fire still heats but the fan won't push the warm air out. In areas that require it, the valve has a 7-day pilot-on-demand timer that shuts the pilot off after 7 days without use, and you relight it manually.

It comes with an on/off rocker switch, and flame height and heat output are set with a manual HI/LO knob on the gas valve behind the lower grille. A wall switch or thermostat can be added on low-voltage wires. The option list includes a remote with thermostat, a deluxe on/off remote, a wireless on/off wall switch, a wall-mount thermostat, and a wireless wall-mount thermostat, since no remote comes in the box.

It needs an opening at least 23-1/2 inches high, 33-1/2 inches wide at the front, 24-1/2 inches wide at the back, and 16-3/8 inches deep. The fireplace has to be a wood-burning masonry or factory-built fireplace. Firebrick and fastened-in smoke shelves or baffles can be removed to reach the minimum, but the existing fireplace's sheet metal can't be cut.

It vents up the existing chimney through two 3-inch flexible liners, one for exhaust and one for outside combustion air, ending at an approved 3 x 3-inch cap. Kozy Heat's #816 kit includes 36 feet of expandable 3-inch pipe and a round cap, and the manual lists approved caps from Ameri-Vent, BDM, Simpson DuraVent, ICC, Metal Fab, Olympia Chimney Supply, and Selkirk. The chimney must be 10 to 50 feet tall, at least 7 inches inside (factory-built) or 6 x 8 inches (masonry), and it can't serve any other appliance.

Yes, but it's manufactured for natural gas, so propane takes a certified conversion done by a qualified installer before the logs go in. The manual's parts list shows the propane conversion kit as OCK-S50A, and its table of contents lists gas conversion as sold separately, so confirm with your dealer whether a kit is included with your unit. On propane it's rated at 36,500 BTU/h maximum.

Combustible 3/4-inch trim can start 12 inches above the top of the insert, and a 9-inch-deep mantel can start at 16 inches, getting 1 inch deeper for every added inch of height. With the low mantel kit on the rectangular or prairie screen front, a 6-inch mantel can start at 11 inches. Side walls need 12 inches, twice what the Chaska 34 needs, and the ceiling must be at least 55 inches above the fireplace enclosure floor. The manual doesn't give a separate TV rule, so plan any TV around these clearances.

Plan on a screen front and a shroud—the brochure lists the front as required and says the shroud is required for installation. Fronts include black, brushed stainless, or antique copper overlay rectangular, black prairie, and vintage bronze arched mission, and shrouds come in black at 27 x 40, 30 x 44, or 33 x 46 inches, or as a blank shroud. The fan kit comes standard, and black brick or Canyon Creek firebox panels and a low mantel kit are optional.

Yes to both. The manual says it may be installed in a bedroom, and in an aftermarket, permanently located manufactured home (USA only) or mobile home where local codes don't prohibit it. It still has to go into an existing wood-burning fireplace and chimney that meet the size requirements.