Vulcan-Hart SG66 Gas Heater User Manual


 
TROUBLESHOOTING
Certain procedures in this section require electrical test or measurements while
power is applied to the machine. Exercise extreme caution at all times and follow Arc Flash
procedures. If test points are not easily accessible, disconnect power and follow Lockout/Tagout
procedures, attach test equipment and reapply power to test.
ALL MODELS
SYMPTOMS POSSIBLE CAUSES
Blower motor doesn’t run with 1S in “Cool Down” or “On”
position.
1. Line voltage.
2. Power switch (S1) malfunction.
3. Switch (S3) malfunction.
4. Interconnecting wiring malfunction.
5. Motor inoperable.
Blower motor doesn’t run in “On” position. “Cool Down”
functions OK.
1. Door switch malfunction.
2. Power switch contacts inoperative.
3. Interconnecting wiring malfunction.
Blower motor doesn’t run in “Cool Down” position. Runs
OK in “On” position.
1. Power switch malfunction.
2. Interconnecting wiring malfunction.
Gas does not ignite; No spark; No Ignition Light ON.
1. Shorted electrode on ignitor/flame sense.
2. Ignitor cable (high voltage) OPEN.
3. Heat relay (R3) malfunction.
4. Transformer (T1) inoperative.
5. High limit thermostat open.
6. Interconnecting wiring malfunction.
7. Ignition Module malfunction.
Sparks but gas does not ignite.
1. Gas solenoid valve OFF or inoperative.
2. Manual gas valve CLOSED.
3. Gas supply OFF or Insufficient gas pressure.
4. Interconnecting wiring malfunction.
5. Ignition Module malfunction.
Gas ignites but will not maintain flame.
1. Igniter lead connections malfunction.
2. Ignitor ground inoperative.
3. Ignitor/flame sense malfunction.
4. Insufficient gas pressure.
5. Snorkel vent plugged, obstructed or missing.
6. Incorrect polarity from transformer (T1) to Ignition
module.
SG SERIES GAS CONVECTION OVENS - TROUBLESHOOTING
F45525 Rev. A (0315) Page 32 of 33