MartinLogan VENT-FREE FIREPLACE SYSTEMS 33ISDG User Manual

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23D8036 
19
ELECTRICAL WIRING (MILLI-VOLT)
The milli-volt valve is a self-powered combination gas control 
THAT DOES NOT REQUIRE 110 VAC TO OPERATE.
Figure 20 - Wiring Diagram
Optional Wall
Switch or Remote 
Receiver
Switch
On/Off
Switch
On/Off
Switch
Wall
Switch
ODS 
Pilot
Millivolt 
Valve
 TH = 3
TP = 1
TP/TH = 2
ODS 
Pilot
Spade 
Terminal
Label all wires prior to disconnection 
when servicing controls. Wiring 
errors can cause improper and 
dangerous operation. Verify proper 
operation after servicing.
W
A
RNING
CONNECTING OPTIONAL WALL SWITCH OR THERMOSTAT
1.  Use 18 awg, two-wire cable, 15 feet maximum length.
2.  At one end of the cable, connect both wires to the wall switch or thermostat. At the other end, connect one wire to TP/TH 
and one wire to TH, or connect the wall switch/thermostat to the two male (0.25") terminals on the left side of the unit. 
The color of the wires does not matter. 
See Figure 20 and installation instructions 
provided with optional wall switch, thermo-
stat or remote control for wiring instructions. 
A maximum length of 15 feet of 18awg two 
conductor wire is to be used for wall switch 
or thermostat installations. 
Note thermostats and switches must 
be suitable for milli-volt operation.