Real Fyre Graystone Vent-Free Fyre Spheres

In a factory-built fireplace, follow that fireplace maker's clearances. Otherwise Peterson requires:

• Side walls: 6 inches from the side of the fireplace opening to a combustible side wall.
• Ceiling: 42 inches from the top of the opening.
• Above the opening: at least 12 inches of noncombustible material such as brick, stone or marble. With a fireplace hood, 10 inches.
• Mantel: how far a wood mantel may stick out depends on its height. At 20 inches above the opening it may project 2.5 inches without a hood, or 10 inches with one. The manual has the full chart.
• Floor: if the burner sits less than 6 inches above the floor, 12 inches of noncombustible hearth in front of the fireplace.

If you cannot meet these clearances, Peterson says the set must be run with the chimney damper open. A fireplace hood is strongly recommended under a wood mantel.

Is your room big enough?

A vent-free fire takes its air from the room, so the room has to be large enough for the burner. The rule in the National Fuel Gas Code is 50 cubic feet for every 1,000 BTU. Multiply the room's length, width and height in feet, then multiply by 20: the answer is the most BTU the room can take. Rooms that open into it without a door count as part of the space.

The low setting is available with the electronic variable remote. Vent-free heaters over 10,000 BTU may not be installed in a bedroom or a bathroom, so this is not for those rooms. In a very tightly sealed home, or above 2,000 feet, you may need to open a window an inch or two while it runs.

Control

On/Off Remote. A standing pilot plus a handheld remote that turns the fire on and off. Runs on batteries that come in the box.

Electronic Variable Remote. Electronic ignition with an on-demand pilot, so no pilot burns while the fire is off, plus flame height on the remote. Runs on batteries that come in the box.

A vent-free set goes into a wood-burning fireplace, with the damper open or closed, or into a listed vent-free firebox, by a licensed gas installer.

• Where it is allowed: not in California, not in bedrooms or bathrooms in most states, and not in a room smaller than the burner's minimum; check the room-size table on this page and your local code before ordering.
• Gas: a dedicated 1/2-inch line with a shutoff; the burner's ODS pilot shuts the gas off if the room's oxygen drops.
• Clearances: the mantel and side-wall distances on this page are the burner's own; they apply whatever fireplace it goes into.
• Logs: placed exactly by the diagram; a moved log on a vent-free burner makes soot.
• Controls: manual, remote or thermostat; the electronic versions take batteries or a 110-volt outlet in the firebox.

• Sphere carton: the full set for your size. Use exactly that number. Peterson warns that adding spheres makes the burner unsafe.
• Burner carton: burner with valve and ODS pilot assembled, removable front cover, remote and batteries, gas connector, floor screws, a damper clamp for vented installations, and black glass to spread on the firebox floor around the burner (10 lb with the 18 inch, 15 lb with the 24 inch).

• It is a supplemental heater, not the main heat for a home, and it must not be left on unattended or while anyone is sleeping.
• Burning gas makes water vapor. If windows start to fog, open a window or the damper a little.
• Expect some odor and light smoke for the first four to six hours of use while factory coatings burn off. Ventilate well during that time.
• Candles, air fresheners, sprays and fresh paint in the room can cause odors when the fire is on.
• Keep ceiling fans and vents from blowing into the fireplace. Glass doors must be fully open and a screen in place.
• Have it cleaned and checked by a qualified technician at least once a year. Peterson requires it for the warranty, and the ODS pilot is sensitive to dust, lint and pet hair.
• Installation is by a qualified gas professional. In Massachusetts that must be a licensed plumber or gas fitter.
• Some soot on the spheres is normal with this burner, Peterson says. Soot in the firebox or the room is not, and means it needs service.
• Do not burn wood in the fireplace once it is installed.

The Graystone Vent-Free Fyre Spheres vent-free set is a heater that looks like a fire: all of the burner's heat comes into the room, so a 30,000 BTU set warms a living room the way a small furnace would, with the logs glowing red where the flame runs through them. The flame is blue at the base and yellow above, lower and tighter than a vented flame because it burns clean by design, and the ceramic logs radiate heat long after the burner is off. It runs from a knob, a remote or a thermostat, and it can run with the damper shut, which is the whole point.

Trade-offs to know

• A clean-burning flame is a smaller flame; if you want the tall, lazy fire of a wood log, a vented set gives it and a vent-free set does not.
• It puts moisture and the products of combustion into the room. Some people notice the smell on a new set; most do not after the first burns.
• It is not allowed everywhere, and the room must be big enough.

Living with it

Brush the logs gently once a season and never move them from the diagram; a log out of place makes soot on the ceiling. Keep the ODS pilot dust-free. Run a window cracked in a tight house. Change the control batteries yearly.

Warranty

Source: R.H. Peterson Real Fyre limited warranty, printed in the burner manual linked above. Register the set with Peterson after installation.

• G23 vent-free: installation and owner's manual