8 |
0.14″ Pressure switch contacts open |
1 |
Check pressure switch for proper operation. Replace pressure switch if moisture has entered switch. Check venting for blockage. Clear if present. |
18 |
High Limit Operation: Burner oft until outlet water temperature drops below 180 °F |
1 |
Happen when heat demand is lower than lowest firing rate of boiler, such as operation of single, small zone. Check system for: |
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• Verify boiler and system are full of water. |
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• Verify system does not have trapped air. |
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• Inspect and verify system piping and components. |
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• Verify piping agrees with boiler manual recommendations. |
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2 |
Use contact thermometer to check outlet water temp. Compare to temperature shown with display in “INFO” mode (“1” in first digit). Replace return temperature sensor if results are not close. Replace control module if sensor replacement doesn’t solve problem. |
19 |
High Limit Operation: Burner offuntil return water temp, drops below 190 °F |
1 |
Check system for: |
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• Verify boiler and system are full of water. |
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• Verify system does not have trapped air. |
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• Inspect and verify system piping and components. |
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• Verify water flow is not reversed or pipes crossed. |
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2 |
Use contact thermometer to check return water temp. Compare to temperature shown with display in “INFO” mode (“2” in first digit). Replace return temperature sensor if results are not close. Replace control module if sensor replacement doesn’t solve problem. |
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High Limit Operation: Return temp, is higher than supply temp. |
1 |
• Verify boiler and system are full of water. |
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• Verify system does not have trapped air. |
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• Inspect and verify system piping and components. |
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• Verify water flow is not reversed or pipes crossed. |
24 |
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2 |
Use contact thermometer to check return water temp. Compare to temperature shown with display in “INFO” mode (“2” in first digit). Replace return temp, sensor if results are not close. Replace control module if sensor replacement doesn’t solve problem. |
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High limit operation: Outlet water temp, increased too quickly. Non-adjustable default setting 9.8°F/sec |
1 |
Indicates flow rate too low. Check system for: |
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• Verify boiler and system are full of water. |
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• Make sure system does not have trapped air. |
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• Inspect and verify system piping ana components. |
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• Verify piping agrees with boiler manual recommendations. |
25 |
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2 |
Verify operation of boiler circulator: |
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• Check voltage at circulator junction box to ensure 120 vac when boiler operates. If no voltage, check wiring and wiring connections. |
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• High voltage terminal strip terminals 5 and 6 should show 120 vac for space heating; terminals 3 and 4 should show 120 vac for DHW. Replace circulator if powered but not operating. |
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• Replace line voltage wire harness if necessary. Replace control module if wire replacement doesn’t resolve. |
26 |
Aquastat contacts open or LWCO contacts open or 3.5″ Switch open |
1 |
Verify proper setting of control. |
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Water temp too high, wait for temperature to drop below 180 degrees. |
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2 |
Check water level in boiler, fill if low. |
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Press LWCO reset switch on display panel |
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If problem still exists, check LWCO probe and board according to manufacturer’s instructions. Replace if necessary. |
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3 |
Check pressure switch for proper operation. Replace if moisture has entered switch. Check venting for blockage. Clear if present. |
29 |
Blower turning when it should be off. |
1 |
Check boiler wiring against wiring diagram. |
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Replace line voltage and low voltage wiring harnesses if necessary. Replace control module if wire replacement doesn’t resolve. |
30 |
High limit operation: Temperature rise across boiler too high. |
1 |
Flow rate too low. |
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Check system for: |
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Verify boiler and system are full of water. |
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Inspect and verify system piping and components. |
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Verify piping agrees with boiler manual recommendations. Make sure system pressure drop is not too high. |
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2 |
Verify operation of boiler circulator. |
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Check voltage at circulator junction box to ensure 120 vac when boiler operates. If no voltage, check wiring and wiring connections. |
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High voltage terminal strip terminals 5 and 6 should show 120 vac for space heating; terminals 3 and 4 should show 120 vac for DHW. |
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Replace circulator if powered but not operating. |
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Replace line voltage wire harness if necessary. |
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Replace control module if wire replacement doesn’t resolve. |
61 |
Pressure switch contacts closed. |
1 |
Check pressure switches for proper operation. |
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Replace pressure switch if moisture has entered switch. |
65 |
Blower not operating when turned on. |
1 |
Turn off power to boiler. Remove line voltage connector at blower. Restart boiler and check voltage across blower plug terminals. If 120 vac is NOT present, inspect wiring and tightness of connections. |
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Replace line voltage wire harness if necessary. |
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Replace control module if wire harness replacement doesn’t resolve. |
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2 |
If 120 vac is present on blower wire harness, replace harness and retry. If problem persists, replace blower motor. |