York P4LBX20F19001, P3DHX12F08001 R7184 LED Diagnostic Light, R8184N Notes, Preliminary Steps

R7184 LED DIAGNOSTIC LIGHT

The LED diagnostic light has several functions. It indicates the state or mode in which the oil burner is operating. It will also indicate fault conditions, and help determine cad cell resistance while the burner is operating.

NORMAL CONDITIONS:

The LED diagnostic light will turn on when the burner enters the carryover state; the point at which ignition spark is on, and will remain on through the run state, where the ignition spark is termi- nated but the burner continues to fire.

The LED diagnostic light will turn off at the end of the burner cycle as the R7184 enters the idle state, and will remain off until the next heating cycle.

FAULT CONDITIONS:

If the LED diagnostic light is flashing quickly; 1 Hz (½ second on / ½ second off), the R7184 is in the lockout state or in restricted mode. To exit the lockout state, press the reset button.

If the LED diagnostic light is flashing slowly; ¼ Hz (2 seconds on / 2 seconds off), the R7184 is in the recycle state. This indicates that flame sensing was lost after the lockout timer expired during the ignition carryover state. The R7184 will return to the idle state within 60 sec- onds.

CAD CELL CONDITION:

If the LED diagnostic light is off, the cad cell is not sensing flame.

If the LED diagnostic light is on, the cad cell is sensing flame, or viewing ambient light.

The resistance of the cad cell may be checked while the R7184 is in the run state by pressing the reset button. The LED diagnostic light will flash the follow- ing code:

Table C-1: Cad Cell Resistance

Flashes Resistance in Ohms

1Less than 400

2Between 400 - 800

3 Between 800 – 1600

4 Between 1600 - 5000

22

Troubleshooting

IMPORTANT:

Due to the potential hazard of line voltage, only a trained, ex- perienced service technician should perform the trouble- shooting procedure.

PRELIMINARY STEPS:

Check the diagnostic light for indications of burner condition. Refer to R7184 LED DIAGNOSTIC LIGHT section for details.

When simulating a call for heat at the R7184, disconnect at least one thermo- stat lead wire from the T1 - T2 terminals to prevent damage to the thermostat. Neglecting this procedure may burn out the heat anticipator of a standard 24 VAC thermostat, or cause harm to compo- nents within a micro-electronic thermo- stat.

Before checking the oil primary control, perform these preliminary checks, (repair or replace controls as necessary):

•check the power supply; fuse box or breaker, any service switches, all wir- ing connections, and burner motor re- set button (if equipped).

•check the limit switches to ensure that the switch contacts are closed.

•check the electrode gap and position.

•check the contacts between the oil primary control and the electrodes.

•check oil supply (tank gauge).

•check the oil nozzle, oil filter, and oil valves.

•check the piping or tubing to the oil tank.

•check the oil pump pressure.

CHECK OIL PRIMARY CONTROL AND IGNITOR

If the trouble does not appear to be in the burner or ignition hardware, check the oil primary control and the ignitor by using the following equipment:

screwdriver.

voltmeter (0 - 150 VAC)

insulated jumper wires with both ends stripped.

Electrical Shock Hazard.

Troubleshooting is done with the system powered. Be careful to observe all nec- essary precautions to prevent electrical shock or equipment damage.

Preliminary Checks:

Make sure that limit switches are closed and that contacts are clean.

Check for line voltage power on the oil primary control black and white lead wires.

Refer to Table C-4 or C-5 for further trou- bleshooting information.

R8184N NOTES

The R8184N oil primary control is a standard intermittent ignition control with a 45 second timing.

The low voltage wires to the L4064W fan/limit controller must be connected to “F2” and “T2”. Incorrect wiring connec- tions will cause nuisance lockouts.

The R8184N oil primary control has an enhanced power supply to enable pow- ering the L4064W fan/limit controller heater circuit. Substitute oil primary con- trols such as the R8184G and others will not work with this system.

Cad cell resistance can be checked with an ohmmeter. During normal combus- tion, the resistance should be less than 1500 Ω , preferably under 900 Ω . To measure the resistance, start the oil burner. After one minute of operation, place a temporary jumper across “F1” and “F2”. Remove one of the cad cell wires then read the resistance by con- necting the ohmmeter probes to the two cad cell wires. Next, remove the jumper. The oil burner should stop immediately. Shut off the power to the furnace then re- fasten the cad cell wire to the terminal from which it was removed. Restore power to the furnace to continue normal operation.