Nordyne M3RL Series To Remove the Burner Assembly, To Remove the Burner Orifices

To Remove the Burner Assembly:

1.Follow the instructions “To Turn Off the Fuel Supply to the Appliance.”

2.Disconnect the flame sensor wire from the burner box.

3.Disconnect the ignitor wires at the 2 pin plug. This is a locking quick connect and both sides of the lower section must be depressed in order to be separated.

4.Remove the wires from the terminals of the gas valve.

5.Disconnect the rubber pressure tubes from the gas valve and the burner box.

6.Remove the burner access cover plate from the burner box.

7.Remove supply gas piping from the gas valve.

8.Carefully remove the burner assembly fas- teners and remove the burner assembly from the appliance. Keep the fasteners that were removed. Note that the burner box may have hooks near the top and on the right and left hand sides. To remove this type of burner box, lift the burner box upwards and then remove the box from the unit.

To Remove the Burner Orifices:

1.Remove the four (4) fasteners that secure the gas manifold to the burner box, as shown in Figure 25. Carefully remove the gas manifold assembly from the burner box. Note that the gas manifold assembly consists of the gas valve, the gas manifold, and the orifices.

2.Carefully remove the burner orifices from the gas manifold, as shown in Figure 25.

!CAUTION:

Caution: Do not re-drill the burner orifices. If the orifice size must be changed, use only new orifices.

Note: The size of the new orifices that will be installed into the unit will depend upon the type of conversion (sea level or high altitude; natural gas or LP gas).

To Convert the Unit to the Alternate Gas

1.Remove the orifice bag from the manifold of the unit.

2.Install the appropriate gas burner orifices into the gas manifold. Remember if in- stalling at altitudes above 4,000 feet to install the proper orifices, shown in Table 8. When installing the new orifices, DO NOT use pipe joint compound on the orifice threads. Screw the orifices into the manifold by hand until snug to eliminate cross threading, then tighten with a wrench. Before installing an orifice, check the face or side of the orifice for the drill number to ensure that it is the appropriate size.

3.For the conversion to the alternate fuel, the gas valve regulator cap must be turned over, as shown in Figure 23. You will unscrew the cap and reinstall for your in- stallation. After reinstalling the cap, you will be able to read "NAT" for the conversion to natural gas or "LP for the conversion to LP gas.

Furnace	Furnace Rating	No. of	Elevation		Elevation		Elevation		Elevation		Elevation
	Plate Input
Model Number			0 - 2000		2000-4000		4000-6000		6000-8000		8000-10000
		Burners
	(Btuh)
M3RL -			Nat	LP	Nat	LP	Nat	LP	Nat	LP	Nat	LP
060A-A/BW	60,000	4	50	57	50	57	51	58	51	58	52	59
080A-A/BW	80,000	5	49	1.15 mm	49	1.15 mm	50	57	50	57	51	58

Table 8. Approximate Orifice Size for Natural and LP Gases

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