ONYX2 Owner's Manual
4
RSF Woodburning Fireplaces
GENERAL SPECIFICATIONS
The ONYX2 fireplace is environmentally friendly as well as efficient. It is approved by the United States
Environmental Agency (EPA) at an emission rate of 4.5 grams per hour.
THE COMBUSTION CONTROL SYSTEM
Since the door is sealed, all combustion air must come through the ONYX2's draft control. This control has a
bimetal coil to allow more air when the unit is cold, and less air when the unit is hot, guarding against overheating.
It can be controlled either manually with the lever that is located on the right below the door, or automatically with
an optional electric wall thermostat.
For the first few days, it is best to operate the fireplace with the manual control fully open (moved to the right as
far as possible). Just control the fire as you would any normal fireplace, using one or two logs at a time for a
smaller fire, or more logs for more heat. Once you become familiar with operating the fireplace with the control
open, you can start experimenting with lower settings. Remember: when the fireplace is hot, the control will not
need as much movement to reduce the fire as when it is cold. The bimetal coil will already have shut the damper
part way.
OPTIONS
There are many different ways you can finish your ONYX2
1
fireplace. You can choose to install louvers, they are
available in various colors (regular black: FO-ONLB, regular gold: FO-ONLG, regular pewter: FO-ONLP or classic
black: FO-ONLC) or no louvers at all (FO-F2).
If you choose to install your ONYX2 fireplace without any louvers, you MUST install the Clean Face Option (FO-
F2) along with two Gravity Vent Kits (FO-V2). Gravity vent dampers CANNOT be installed on a Clean Face
ONYX2. Furthermore, we recommend that you do not install any option requiring electricity or a thermal switch
inside your fireplace since it will be difficult to access those components after the fireplace facing is covered with
non-combustible materials. If you decide nevertheless to install electricity or a thermal switch in your Clean Face
ONYX2, remember that you may eventually have to break through the non-combustible finishing to access the
electrical box or the thermal switch for servicing.
To simplify the installation of thin non-combustible materials such as ceramic tile or sliced brick, we have
designed a rock retainer kit. It is not designed or required for full brick or stone. With a Louvered ONYX2, you can
choose to leave all the black metal completely exposed or completely covered with non-combustible material.
Whether you have chosen a Louvered or Clean Face ONYX2, the FO-KN kit will help you finish the facing of the
fireplace as you wish. Thin materials can also be installed directly on the face of the ONYX2 using high
temperature silicone as glue, without a rock retainer kit.
For increased air circulation and marginally more heat output, you can add the Circulating Internal Blower (FO-
FDHB5-N) to your Louvered ONYX2 or the Inline Fan (FO-CIF) to your Clean Face ONYX2.
NOTE
: The Onyx2 is equipped with a floor shield to protect the floor under the fireplace. This floor shield is
made of two parts: the front part is insulated; the back part is a simple part. Both parts are screwed together and
factory installed to cover the entire floor below the firebox. It must never be removed. Only when installing the
Internal Blower Option, the floor shield must be modified. Follow the internal blower installation instructions but
before reinstalling the floor shield, remove the screw, slide the back part over the front part and screw them back
together. If you ever remove the internal blower make sure to extend the shield again.
If you have any rooms directly above or adjacent to the room with the fireplace that you would like to heat, you
may want to consider the Gravity Vent Kit
2
(FO-V2). The gravity vent distributes hot air to these rooms and
requires no blower to assist its operation. With a Louvered ONYX2, you could also consider installing Dampers
(FO-D) on your gravity vents. The dampers will enable you to choose between sending the heated air to the
gravity vent outlet or keeping it in the fireplace room.
For constant heat, day and night on a Louvered ONYX2, you will be surprised by what the Thermostat Option
(FO-FDHC4) can do for you. This option provides you with the necessary parts to automatically control the draft
control via a wall thermostat. It will keep your room temperature as even as though you were heating with oil, gas
or electricity, except you will find wood heat more comfortable. Do not install this Thermostat Option (FO-FDHC4)
1
You can also refer to the configured option list on page 24.
2
Not allowed in a mobile home installation.
