Lennox Hearth DIRECT-VENT RAVENNA SDVI33/40 - Manual (Page 20)

20 NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
Operating Options
The rocker switch on your gas appliance is used to turn the burner on
and off while the pilot is on. The rocker switch can be installed in the hole
in the right side of the top surround panel or in the hole in the panel to
the left of the igniter button. The hole in the panel is covered by a label
which must be carefully cut out before installing the rocker switch. The
switch must be disconnected from the coil of wire to which it is attached,
the plastic nut unscrewed from the back side of the switch and then the
switch can be inserted into the hole at either location. If the switch is to
be located in the surround, route the wire behind the igniter bracket and
through the hole in the lower right side of the appliance. Attach the three
plastic adhesive wire restraints (found in the bag in the firebox) to the
side surround panel. Feed the wire through these restraints and up to the
switch. Care should be taken to ensure the wire does not come in contact
with the hot surfaces of the firebox. Reconnect the wires to the switch.
A wall­mounted switch, a millivolt wall thermostat, or a remote control,
can be used to supplement the rocker switch. The gas valve is powered
by millivolts generated by the pilot assembly. This millivolt system is very
sensitive to electrical resistance, therefore, make sure all connections are
tight, clean and free from corrosion. Do not splice any millivolt wires.
Consult the table on this page to determine the proper gage of wire for
the thermostat or wall switch connections. This table refers to the total
length of the wire (out to the switch and back). The thermostat must be
a millivolt type. A 24­volt furnace thermostat will not work. Never hook
up household current ­ 120 Volts ­ to the millivolt system. It is not rec­
ommended to hook up any more than two switches to the appliance (for
example a rocker switch and a wall thermostat). Additional switches may
affect the system resistance and increase the chance of the burner not
igniting. Follow the instructions included with the thermostat or remote
control for wiring.
The thermostat, remote control and rocker switch will turn the burner on
and off independently. Be sure to set the rocker switch to the “OFF” posi­
tion when using the thermostat or remote control and set the thermostat
or remote control to the lowest temperature when you wish to use the
rocker switch only, otherwise one may override the other. If a remote
thermostat is to be used with the appliance, do not place the receiver
under the firebox.
Thermostat Wire
Wire Size Maximum Length
12 Gage 100 Feet
14 Gage 64 Feet
16 Gage 40 Feet
18 Gage 25 Feet
20 Gage 16 Feet
Millivolt Control System
This fireplace operates on a millivolt control system. As such, no addi­
tional power supply is needed for the fireplace to heat. The pilot assembly
contains a thermocouple, that when heated by the pilot flame, generates
electricity (millivolts­ mV=1/1000 of a volt) which opens a valve allow­
ing gas to flow to the pilot assembly. The pilot assembly also contains a
thermopile, that when heated by the pilot flame, generates electricity that
flows to terminal #1 (labeled THTP) on the gas valve. When the electricity
is conducted from terminal #1 through the on/off switch, thermostat,
or receiver of the remote control to terminal #3 (labeled TH) on the gas
valve, the main burner will ignite.
CAUTION: Label all wires prior to disconnection when servic-
ing controls. Wiring errors can cause improper and dangerous
operation.
ATTENTION: Au moment de l'entretien des commandes,
étiquetez tous les fils avant de les débrancher. Des erreurs
de cáblage peuvent entraîner un fonctionnement inadéquat et
dangereux.
Millivolt Control Schematic
Sparker
Pilot Hood
ON/OFF Rocker Switch, Thermo-
stat, or Remote Thermostat
Pilot Assembly
Thermocouple
Piezo Igniter
White
Gas Inlet
Pilot Gas Line
Thermopile
Brown
Figure 18
Wiring Terminals
TH
TP
TH/TP