IC-SA-1511 (02/2014)
V/LNV Series Manual
5-3
5.4 — Impeller and Inlet Cone
5.4 — Impeller and Inlet Cone
Proper clearance between the impeller and the inlet housing set at 3/8” nominal. Adjust the inlet cone so it
is centered in the inlet of the impeller and tighten the bolts. There should be no contact between the inlet
cone and the impeller. Inserting a bar through the impeller blade and using it as a lever will only damage the
blade.
5.5 — Firing Head Inspection
Open side access panels to view the drawer assembly. Inspect the lead wire to the ignition electrode. It
must be firmly attached and the insulation should be clean and free of cracks. The oil nozzle should be
inspected periodically.
If fibrous material is discovered in the gas spud ports, remove the gas spud and back flush with shop air.
Further inspection of gas piping and gasket connections must be made to isolate the contaminate source.
Be sure to orientate the gas spuds in the correct position when reassembling the gas spuds.
5.5.1 — Drawer Assembly
The drawer assembly may be removed for inspection and/or service. For drawer assembly drawings, refer
to section 4.4.4 for firetube applications and 4.4.5 for watertube or cast iron applications.
1.
Shut off the burner, position the switch to “Off”.
2.
Shut off all electric power to the burner.
3.
Disconnect the fuel lines from the drawer assembly access cover.
4.
After making note of where the bolts are located in relationship to the access cover slots, remove the
drawer assembly access cover bolts. Pull the drawer partially out of the housing. Reach inside to
disconnect the ignition cables from the electrodes for direct spark applications. Pull the drawer
assembly completely out of the housing.
5.
To reinstall the drawer assembly, insert it part way into the housing, connect the ignition cables, if
applicable, and seat the assembly fully. Install the access cover bolts loosely. Slide the cover into the
original location and tighten the bolts. Reconnect the fuel lines.
5.6 — Pilot and Ignition Electrode
Failure to keep the ignition electrode clean and properly set can cause faulty operation. Not only must the
gap be correct, but the electrode points must be carefully located with respect to the nozzle. Sometimes
difficulty in securing the electrodes in their clamps can be corrected by using light metal shims around the
porcelain. Defective or cracked porcelains require replacement to prevent short circuiting of the spark. A
gradual wearing away of the electrode tips may require re-spacing of the points or replacement of the
electrode.
The pilot should be checked monthly for loosening of components and carbon buildup. Before removing
the pilot, ensure that the fuel supply is shut off.
On direct spark oil units, once the drawer assembly has been removed, check the electrode to nozzle gap
and adjust if necessary. Refer to the pilot and drawer assembly drawings in Chapter 4.