Monessen Hearth DFX24C - Manual (Page 24)

4 33D4047
DFX & DBX Series Vent Free Fireplaces OPERATING INSTRUCTIONS
THERMOSTATIC CONTROL LIGHTING INSTRUCTIONS
TO TURN OFF GAS TO HEATER
1. Turn control knob clockwise to OFF position to completely shut off the heater.
. If applicable: Turn off all electric power to the heater.
1. STOP! Read the safety information .
. Make sure the manual shutoff valve is fully open.
3. This heater is equipped with an ignition device (piezo) which automatically lights the pilot.
4. Refer to Page 22, Figure 28 for the location of the piezo ignitor and control knob. Turn control knob
clockwise to the OFF position.
5. Wait 5 minutes to clear out any gas. Then smell for gas, including near the floor. If you smell gas, STOP!
Follow safety instructions under What to do if You Smell Gas, Page 23. If you do not smell gas, go to
the next step.
6. Turn the gas control knob counterclockwise to the IGN position. Figure 32. Push in and hold
control knob for 5 seconds.
7. With the control knob pushed in and held, push and release the piezo ignitor button to light the ODS
pilot. The pilot is located on the right side of the heater, behind the front log and in front of the burner.
If piezo ignitor does not light the pilot, see match Lighting instructions, Page 26.
8. Hold the control knob in for an additional 10 seconds to prevent the ODS pilot from shutting off the gas
while the thermocouple is warming up.
9. Release the control knob.
• If the knob does not pop out when released, stop and immediately call your service technician or
gas supplier.
• If the ODS pilot will not stay lit after several tries, push and turn the control knob clockwise
to OFF. Release and wait 15 seconds. Repeat steps 6 through 9.
10. Turn control knob to any position between LOW and HIGH. The knob position controls the thermostat
temperature. Figure 32
11. The heater is now in proper operation. The following procedure should be used to achieve thermostatic
control of the desired room temperature.
FP2576
rotate control knob
Figure 32 -
Control Knob
a. Operate unit at higher setting until desired room temperature is
achieved.
b. At the desired temperature, slowly turn the knob clockwise and stop
rotating when flame disappears.
c. Thermostat is now set to maintain the current room temperature.
d. As the room temperature decreases, the thermostat valve will open to
ignite the front and rear burner.
e. When the temperature reaches its set point (knob position), the thermo-
stat valve will again shut off the burner.
f. This is the normal cycle of the heater.