7.After the flame ignites, visually inspect the burner assembly to ensure that the flame is drawn directly into the center of the heat exchanger tube, as shown in Figure 23. The end of the flame will be out of sight around the bend of the heat exchanger tube. In a properly adjusted burner assem- bly, the flame color should be blue with some light yellow streaks near the outer portions of the flame.
NOTE: Until all of the air is bled out of the gas line, the hot surface ignitor may not ignite the gas. If the ignition control locks out, turn the thermostat to its lowest setting and wait one minute then turn the thermostat to a point above room temperature and the ignitor will try again to ignite the main burners. This process may have to be repeated several times before the burners will ignite. Once the burners are lit, check all gas connections for leaks again with the soap and water solution. If the solution bubbles there is a gas leak which must be corrected. Do not use an open flame to check for gas leaks.
Manifold Pressure
The gas valve for the M3 furnace series is equipped with a special conversion pres- sure regulator cap. The pressure regulator cap is factory set. If the gas valve is con- verted from natural gas to propane gas or vise versa, the manifold pressure of the gas valve will be set to pressure listed in Table 9.
Type of Fuel | Manifold Pressure |
| In. WC |
|
|
Natural Gas: | 3.5 |
Propane (LP) Gas: | 10.0 |
|
|
Table 9. Manifold Pressure
COMPLETING THE CONVERSION
1.Affix the gas valve conversion label found in the package with the orifices to the unit rating plate.
2.Run the appliance through a complete cycle to assure proper operation.
!CAUTION:
To avoid electric shock, personal injury, or death, turn off the power at the disconnect or the main service panel before making any electrical connections.
ELECTRICAL WIRING
General
Electrical connections must be made in accor- dance with all applicable local codes and ordi- nances, and with the current revision of the National Electric Code (ANSI/NFPA 70).
For Canadian installations electrical connec- tions and grounding must be done in accor- dance with the current Canadian Electrical Code (CSA C22.1 Part 1) and/or local codes. If any of the original wire as supplied with the furnace must be replaced, it must be replaced with wire having a minimum temperature rating of 105°C. Refer to the furnace nameplate and Table 8 for electrical requirements.
Line Voltage Wiring
The line voltage (115 volt) to the furnace must be supplied from a dedicated branch circuit containing the correct fuse or circuit breaker for the furnace. See Table 10. An electrical switch should be readily accessible from and within sight of the furnace. See the Wiring Diagram label in the furnace for more details.
The furnace cabinet must have an uninter- rupted, unbroken ground to minimize injury should an electrical fault condition occur. The controls used in this furnace require an earth ground to operate properly. Acceptable meth- ods for grounding are electrical wire or conduit approved for electrical ground service. Do not use gas piping as an electrical ground.
NOTE: Proper line voltage polarity must be maintained in order for the control system to operate correctly. Verify that the incoming neu-
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