Service/Troubleshooting - Modine Manufacturing PDP Installation And Service Manual

servICe & TrouBleshooTIng
Table 24.1 - Troubleshooting
Trouble
Pilot does not light
main burners do not light (Pilot is lit)
lifting flames (see figure 25.2)
Yellow Tipping
(With propane gas, some yellow tipping
is always present.)
Wavering flames (see figure 25.1)
flashback
floating flames (see figure 25.3)
flame rollout (see figure 25.4)
24
Possible Cause
1. Main gas is off.
2. Power supply is off.
3. Air in gas line.
4. Dirt in pilot orifice.
5. Gas pressure out of proper range.
6. Pilot valve does not open.
a. Defective ignition controller.
b. Blown fuse on control board
c. Defective gas valve.
7. No Spark at ignitor.
a. Loose wire connections.
b. Pilot sensor is grounded.
c. Blown fuse on control board
d. Defective ignition controller.
8. Safety device has cut power.
9. Pilot valve is off.
10. Dirty thermocouple contact.
11. Excessive drafts.
12. Pilot orifice Fitting leak.
1. Defective valve.
2. Loose wiring.
3. Defective pilot sensor
4. Defective ignition controller.
5. Improper thermostat wiring.
1. Too much primary air.
2. Main pressure set too high.
3. Orifice too large.
1. Insufficient primary air.
2. Dirty orifice.
3. Misaligned orifice.
1. Drafts across burner
2. Misalignment of burner
3. Cracked heat exchanger
1. Too much primary air
2. Main pressure set too high.
3. Orifice too large.
1. Insufficient primary air.
2. Main pressure set too high.
3. Orifice too large.
4. Blocked vent.
1. Main pressure set too high.
2. Orifice too large.
3. Blocked vent.
6-580.7
Possible remedy
1. Open manual gas valve.
2. Turn on main power.
3. Purge gas line.
4. Check for plugged pilot orifice and clean
with compressed air if necessary.
5. Adjust to a maximum of 14" W.C.
Minimum for Natural Gas - 6" W.C.
Minimum for Propane Gas - 11" W.C.
6. Check wiring for 24 volts to valve.
a. Replace ignition controller.
b. Replace Fuse
c. Replace gas valve.
7.
a. Check all ignition controller wiring.
b. Replace sensor if cracked or worn
c. Replace fuse
d. Replace ignition controller.
8. Check all safety devices (High limit,
pressure switch, blocked vent safety
switch, etc.) Determine and correct
problem. Reset if necessary.
9. Turn gas control knob or lever on
combination gas control to pilot position.
10. Be sure thermocouple contact is clean.
If problem persists replace thermocouple.
11. Find source and re-direct airflow away
from unit.
12. Tighten pilot orifice. Flame impingement
on thermocouple may cause
thermocouple to become inoperative.
1. Replace valve.
2. Check wiring to gas valve.
3. Replace pilot sensor.
4. Replace ignition controller.
5. Verify wiring compared to wiring diagram.
1. Reduce primary air.
2. Adjust to a maximum of 14" W.C.
3. Check orifice size with those listed on
the serial plate.
1. Increase primary air.
2. Check orifices and clean with compressed
air if necessary.
3. Check manifold, replace if necessary.
1. Eliminate drafts
2. Align burner on locator pins
3. Replace heat exchanger
1. Reduce primary air.
2. Adjust to maximum of 14" W.C.
3. Check orifice size with those listed on the
serial plate.
1. Increase primary air.
2. Adjust to a maximum of 14" W.C.
3. Check orifice size with those listed on the
serial plate.
4. Clean/correct venting system.
1. Adjust to a maximum of 14" W.C.
2. Check orifice size with those listed on
the serial plate.
3. Clean/correct venting system.