DVS-36 & DVS-42 INTERMITTENT PILOT TROUBLESHOOTING (continued)
START
Turn gas supply off. Turn thermostat
to call for heat.
Power to module. (24 VAC nominal)
Yes
Spark across Igniter/sensor gap.
Yes
Turn gas supply on.
Pilot burner lights?
Yes
Spark stops when pilot is lit?
Yes
Main burner lights?
Yes
System runs until call for heat ends?
Yes
Call for heat ends.
System shuts off?
Yes
S8600H TROUBLESHOOTING GUIDE
Note: Before troubleshooting, familarize yourself with the startup and checkout procedure.
Check line voltage power, low voltage transformer, limit
N o | control, thermostat and wiring. |
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| Pull ignition lead |
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| and check spark at | N o | Replace module. | |||
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ignition stud. |
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| Spark okay? |
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| Yes |
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•Check ignition cable, ground wiring, ceramic insulator and gap, and correct.
•Check boot of the ignition cable for signs of melting or buckling. Take protective action to shield cable and boot from excessive temperatures.
•Check that all manual gas valves are open. Supply tubing
N o | and pressures are good, and pilot burner orifice is not blocked. |
•Check electrical connections between module and pilot operator on gas control.
•Check for 24 VAC across PV — MV/PV terminals on module. If voltage is okay, replace gas control. If not, replace module.
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| •Note: If S8600H goes into lockout, reset system. | |
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• Check continuity of ignition cable and ground wire. | |||
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| • Check that pilot flame covers electrode. | |
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| • Adjust pilot flame current. Minimum signal should read 1.0 | |
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| • If problem persists, replace module. | |
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| • Check for 24 VAC across |
N o | replace module. |
•Check electrical connections between module and gas control. If okay, replace gas control.
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| Note: If S8600H goes into lockout, reset system. |
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| • Check continuity of ignition cable and ground wire. Note: If | ||
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| ground is poor or erratic, shutdowns may occur occasionally |
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| even though operation is normal at the time of checkout. |
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| • If checks are okay, replace module. |
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| • Check for proper thermostat operation. |
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| • Remove MV lead at module: If valve closes, recheck | ||
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| thermostat and wiring. If not, replace gas control. |
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Troubleshooting ends.
Repeat procedure until troublefree operation is obtained.
Page 36 |
