VS8421 VENTFREE MILLIVOLT GAS VALVE
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WIRING
Follow the wiring instructions furnished by the appliance
wiring diagrams, see Fig. 6.
All wiring must comply with applicable electrical codes
and ordinances.
Disconnect power supply before making wiring
connections to prevent electrical shock or equipment
damage.
1.
Check the power supply rating on the gas valve
and make sure it matches the available supply.
Install the transformer, thermostat, and other
controls, as required.
2.
This valve can be used only in a self-generating
system.
3.
Adjust the thermostat heat anticipator to the 0.1A
at 750 mV rating stamped on the valve operator.
OPERATION
The Ventfree Millivolt Gas Valve System is configured to
include a gas valve, ODS pilot burner, and a millivolt
thermostat. In the ODS pilot burner, the thermopile drives
the operator and the thermocouple operates the power
unit.
As an option, a piezo can be mounted on the valve to
ignite the pilot burner. The piezo creates a spark when
the plunger is depressed. The connecting wires of the
piezo include a terminal to connect to the electrode of the
pilot burner. The piezo is replaceable.
Refer to the installation instructions for the piezo
envelope assembly (part no. 396079), form 69-1206.
Fig. 6. Millivolt system wiring diagram with ODS pilot burner.
Pilot Gas Lighting Procedure
Lighting Standard Pilot (Without Piezo)
1.
Turn the knob counterclockwise
to the
PILOT position, push the knob down, and hold in
position. The pilot valve opens and allows gas to
flow to the pilot burner.
2.
Light the pilot burner while holding down the knob
until a strong flame is present (approximately 60
seconds).
3.
Release the knob. The shaft will move upward and
engage the safety valve lever that opens the safety
valve.
4.
Turn the knob counterclockwise
to the ON
position. On a call-for-heat, the main valve opens
and the main burner ignites.
M11989
HI/LO
REGULATOR
OFF
PILOT
ON
PIEZO SPARKER
GAS
CONTROL
KNOB
HIGH LIMIT
CONTROL
MILLIVOLT
THERMOSTAT
VS8421 HI/LO MILLIVOLT GAS VALVE
ODS PILOT
BURNER
69-1219-1.fm Page 4 Thursday, August 18, 2011 7:32 AM