Wayne P250 series - Page 29

29
TURN GAS SUPPLY OFF, TURN
THERMOSTAT (CONTROLLER)
TO CALL FOR HEAT
POWER TO MODULE (24V
NOMINAL)
YES
SPARK ACROSS
IGNITER/SENSOR GAP
TURN GAS SUPPLY ON.
PILOT BURNER LIGHTS?
YES
SPARK STOPS WHEN PILOT IS
LIT?
YES
YES
MAIN BURNER LIGHTS
YES
YES
YES
SYSTEM RUNS UNTIL CALL
FOR HEAT ENDS?
CALL FOR HEAT END
SYSTEM SHUTS OFF?
TROUBLESHOOTING END
NO
Check line voltage power, low voltage transformer, limit controller, thermostat
(controller) and wiring. Also check end switch on combustion air blower system.
NO
- Check ignition cable, ceramic insulator and gap, and replace part if necessary.
- Check boot of the ignition cable for signs or melting or buckling. Take protective action
to shield cable and boot from excessive temperatures.
NO
- Check that all manual gas valves are open, supply tubing and pressure 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-M/PV terminals on module. If voltage is okay, replace gas
control; if not, replace module.
NOTE: If ignition control goes into lockout, reset system.
- Check continuity of ignition cable and ground wire
- Check flame rod.
- Check electrical connections between flame rod and insulator.
- Check for cracked ceramic flame rod insulator.
- Check that pilot flame covers flame rod and is steady and blue.
- Adjust pilot flame.
- If problem persists, replace the module.
- Check for 24 VAC across MV-MV/PV terminals. If no voltage, replace module.
- Check electrical connections between module and gas control. If okay, replace gas
control or gas control operator.
NO
NOTE: If ignition control goes into lockout, reset system.
- Check continuity of ignition cable and ground wire
NOTE: If ground is poor or erratic, shutdowns may occur occasionally even though
operation is normal at time of checkout.
- Check that pilot flame covers flame rod and is steady and blue.
- If problem persists, replace the module.
- Check for proper thermostat (controller) operation.
- Remove MV lead at module; if valve closes, recheck temperature controller and wiring;
if not, replace gas control.
NO
NO
Repeat procedure until trouble free
operation is obtained.
FIGURE 20
START
NO
NO