Trane GHND-SVX01A-EN - Manual (Page 44)

44 High Efficiency Propeller Fan Gas Unit Heater •
GHND-SVX01A-EN
Trouble Shooting
W. No Spark.
POSSIBLE CAUSE(S)
1. Thermostat not calling for heat.
2. No low voltage.
3. Spark gap closed or too wide.
4. Broken or cracked ceramic on spark electrode.
CORRECTIVE ACTION
• Close thermostat contacts.
• Check for 24V across 24V terminals of S8600.
• Set gap to 0.1".
• Replace pilot assembly.
X. Spark present but pilot does not light.
POSSIBLE CAUSE(S)
1. Loose S8600 connections.
2. Improper gas pressure.
3. Is spark in pilot gas stream?
4. No pilot gas — do not use match to test - presence of gas is easily detected by the
odor.
CORRECTIVE ACTION
• Check all connections, term. PV feeds 24V to pilot valve.
• Check pressure — pressure that is either too high or too low may cause a problem.
• Spark should arc from electrode.
• Check pilot line for kinks. Ensure there are no drafts.
Y. Pilot lights — Main valve does not energize.
POSSIBLE CAUSE(S)
1. Loose S8600 connections.
2. Cracked or broken sensor ceramic.
3. Check sensor/spark lead for continuity.
4. Measure 24 volts from term. MV to term. MV/PV.
CORRECTIVE ACTION
• Check connections-term. MV feeds main valve.
• Replace pilot assembly.
• Replace if needed.