ADDENDA: LOW NOx HEATERS Models 181 to 401 (CONTINUED)

sembly from the burner tray assembly.

4.Use a long ½” socket wrench to remove orifices from the gas manifold.

5.Remove burners by raising the bracket on the back end of the burners up and out of their slots.

6.Reverse above procedure to re-install.

Fig # 9362

LOW NOx BURNER TRAY ASSEMBLY

BURNER TRAY REMOVAL

1.Shut-off main electrical power switch to heater.

2.Shut-off gas upstream of heater.

3.Remove front door.

4.Disconnect gas line from gas valve.

5.Remove (2) screws that mount burner tray to unit, and (4) screws that secure gas valve to jacket.

6.Disconnect wires that terminate at gas valve.

7.Unscrew (4) screws that secure the control box.

8.Disconnect pilot wire from the ignition module.

9.Disconnect wire harness from the combustion blower.

10.Carefully slide out the burner tray assembly.

11.Reverse above procedure to reinstall.

Fig # 9363

IID PILOT

PILOT REMOVAL

1.Disconnect pilot tubing from gas valve.

2.Remove (4) screws from control box. Open the control box.

3.Remove the pilot wire from the ignition wire.

4.Remove (2) screws that mount the pilot bracket to the air manifold assembly.

5.Pull the pilot bracket downwards and outwards.

6.Reverse above procedure to re-install.

GAS VALVE REMOVAL

1.Shut-off main electrical power switch to heater.

2.Shut-off gas supply to the heater.

3.Remove front door.

4.Disconnect gas line from gas valve.

5.Disconnect wires, pilot tubing and bleed line, if required.

6.Remove (2) screws that secure gas valve to jacket.

7.Turn vertical gas pipe from manifold slightly and unscrew gas valve.

8.Reverse above procedure to re-install.

MAIN BURNER AND ORIFICE REMOVAL

1.Remove burner tray. (See Burner Tray Removal procedure above.)

2.Remove (8) screws from the hold-down brackets.

3.Remove (8) screws from the left and right sides of the manifold assembly. Detach the manifold as-

COMBUSTION FAN REMOVAL

1.Remove burner tray. (See Burner Tray Removal procedure above.)

2.Remove (4) screws the mount the combustion blower to the manifold assembly.

3.Reverse above procedure to re-install.

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Raypak NH Burner Tray Removal, Pilot Removal, GAS Valve Removal, Main Burner and Orifice Removal, Combustion FAN Removal