ITEM DESCRIPTION
1.Transformer
2.Control Board
3.E.C.O./Temperature Probe
4.Blower Proving Air Switch
5.Low Voltage Cable Assembly
6. | Line Voltage Cable Assembly | 14. | |
7. | Blower/Motor Assembly | 15. | |
8. | Igniter Assembly | 16. | |
9. | Cable To Control Display Board | 17. | |
10. | Control Display Board | 18. | Low Gas Pressure |
11. | Blocked Outlet Exhaust Switch |
| Switch |
12. | Lower Temperature Probe | 19. | Bocked Inlet Switch |
13. | Wire | 20. | Wire |
| Switch |
| Flow Switch |
FIGURE 17
OPERATION
SEQUENCE OF OPERATION
Typical Control/Appliance Operating Sequence
1.When the control is powered, it should first display “0”, then the input line voltage (“120”), the calibration setting (12), then the actual water temperature in the tank.
2.If the control determines that the actual water temperature inside the tank is below the programmed temperature setpoint less the differential, a call for heat is activated.
3.The control then performs selected system diagnostic checks. This includes confirming the proper state of the air switch and ECO limit device.
4.If all checks are successfully passed, the combustion blower is energized for the
5.When the
6.At the conclusion of the igniter
7.The igniter will remain on for a short predetermined time period, then will be turned off.
8.After an additional 2 seconds, the control will monitor the flame sense probe to confirm a flame is present. If a flame is not verified within this time period, the gas valve will immediately be closed, and the blower will continue to run for approximately 10 seconds. The control will then return to step 2.
9.If a flame is confirmed, the control will enter the heating mode where it will continue heating the tank water until the setpoint temperature plus differential is reached. At this point, the gas valve is closed and the control enters the
10.The combustion blower will run for the duration of the post purge cycle to purge the system of all combustion gases. When the post purge cycle is complete, the blower is
11.The control will now enter the idle state while continuing to monitor the internal tank water temperature and the state of other system devices. If the temperature drops below the setpoint value less differential, the control will automatically return to step 2 and repeat the entire operating cycle. During this idle state, if the control detects an improper operating state for external devices such as the ECO switch, vent switch, pressure switch, etc., the appropriate LED(s) on the Display Board will be illuminated indicating the nature of the fault.
SELF DIAGNOSTIC CONTROLLER
This controller is designed for ignition lockout after three consecutive failed attempts to light. If lockout occurs, the display lights will match Figure 18. Along with this, a numeric message will appear in the display. The following list of ERROR CODES illustrates possible numeric failures.
FIGURE 18
GAS VALVE LED FLASHING
This condition results from a failure to establish burner ignition after three successive trials. In such cases:
1.Investigate the possible cause and remedy any observations.
2.Momentarily depress the button on the display panel to reset the lockout condition.
3.Confirm proper appliance operation.
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| Possible Cause |
| Remedy |
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| 1. | Burner ground wire broken | 1. | Check wire and connection |
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| or corroded |
| at burner |
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| 2. | Connectors unplugged | 2. | Check connections |
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| 3. | Igniter broken | 3. | Replace igniter |
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| 4. | Flame probe faulty | 4. Replace flame probe |
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| 5. | Gas shut off | 5. | Turn on gas supply |
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| 6. | Clogged gas valve | 6. | Replace gas valve |
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| 7. | Faulty gas valve | 7. | Replace gas valve |
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| 8. | Defective control | 8. | Replace control |
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| 9. | Burner improperly adjusted | 9. Adjust burner |
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| 10. | Dirty burner | 10. | Clean burner |
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15