U.S. Boiler Company MPO - IQ, Service Instructions Manual

Page: 64 / 92

64
xIII. TROUBLE SHOOTING (continued)
E.
USE BOILER CONTROL DISPLAY
ERR
AND
ERP
NUMBERS TO DIRECT TROUBLESHOOTING (continued)
Display Status Recommended Corrective Actions
ErP 4
Warning, Cad Cell
Resistance High
(service required)
The cad cell resistance is higher than normal while running, the system is in need of a tune
up.
- Check for proper alignment of the cad cell and clean the eye if necessary.
- Check if the pump is generating adequate pressure.
- Check burner adjustments (refer to burner manufacturers instructions).
- Check for excessive soot build up in the burner and flue.
- Check for flue blockage.
ErP 5
No Ignition,
Check Cad Cell
The cad cell detected some amount of light during the ignition trial, but not enough to enter
run mode.
- Check the cad cell positioning and clean the eye.
- Set the display to show the cad cell resistance.
- Shield the cad cell from light.
If the display shows is less than 20,000 ohms, unplug the cad cell,
if the display does not read 999999 ohms, replace control,
if it does read 999999 ohms, replace cad cell.
- Expose the cad cell to ambient light (generally enough light to read by is adequate)
If the display shows more than 2000 ohms, short the cad cell terminals,
if the display shows more than 5 ohms, replace control,
if less than 5 ohms, replace cad cell.
If the burner still does not light, proceed to "No Ignition",
ERP 20
corrective action.
ErP 9
No Ignition,
Check Cad Cell
The burner lit very late during the trial for ignition and is susceptible to not lighting.
- Check cad cell for proper alignment and clean if necessary.
- Check burner adjustments (refer to burner manufacturers instructions)
- Check electrodes and spring contacts (if equipped) and adjust per manufacturers
recommendations.
- Check if the pump is generating adequate pressure.
- Check the fuel supply lines and filter for obstructions.
ErP 10
No Ignition,
Check Ignition
Transformer
The burner was not lit and spark was not detected. Check the electrodes, spring contacts
(or high voltage wires), and ignition transformer for proper operation.
If spark ignition is functioning acceptably, proceed to "No Ignition",
ERP 20
corrective action.
ErP 18
Internal Error,
Electronics Failure
The Erp 18 display may indicate any one of the following:
Check Oil Primary and Option Panel Displays:
- If Option Panel display shows “
Err 3
“, IQ Option Card Communication Error: the
Erp 18
error is caused by the option card. Replace defective card if error persists
- If The Oil Primary is locked out with “Internal Error” replace control if the error persists.
ErP 20
No Ignition
- Check that fuel tank is not empty.
- Check that the manual shut off valve is open.
- Check that the burner motor is spinning and the pump is generating adequate pressure.
- Check the condition of the nozzle and replace if necessary.
- If a valve is present, check for proper operation.
- Check burner adjustments (refer to burner manufacturers instructions)
ErP 21
No Ignition,
After Flame Loss
During Run
- Check for excessive airflow or draft causing flame to leave burner head.
- Check for back pressure causing flame to be erratic.
Re-ignition Failure, Flame was lost and could not be relit .
ErP 22
Flame Lost During Run
Three Times In A Row
Flame was lost more than the allowed number of times. The burner lights, but does not
remain lit.
- Check that the fuel tank is not empty.
- Check the condition of the nozzle and replace, if necessary.
- Check the fuel supply lines (and filter) for obstructions or air
- Use the pump priming feature to purge the system of air
- Check the burner motor is spinning and the pump is generating adequate pressure.
If present, check operation of the oil valve.
If the problem persists, proceed to the "Cad Cell, High During Run",
ERP 4
corrective action.
TABLE 14B: ExTERNAL DEVICE (Oil Primary, Option Card, etc.) ERROR NUMBERS