| Alarm Codes and Troubleshooting | |
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Alarm ID | Message Name | Action required to Clear/Recover |
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241 | Flame Out of Sequence − Still Present | Shut off gas, check for gas valve leak. |
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250 | Primary Limit Switch Open | Check firing rate on furnace, blockage in heater, and air flow. |
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252 | Discharge Air Temperature High | Check temperature rise, air flow and input rate. |
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270 | Watch Guard − Flame Failure on Ignite | Check for gas flow, ignitor lighting burner, flame sensor current. |
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271 | Watch Guard − Low Pressure Switch Open | Check inches of water column closing pressure of low pressure switch on heat call, measure inches of water |
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| column of operating pressure, inspect vent and combustion air inducer for correct operation and restriction. |
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272 | Watch Guard − Low Pressure Switch Open Run | Check operation of low pressure switch for stuck closed on heat call, measure inches of water column of oper- |
| Mode | ating pressure, inspect vent and combustion air inducer for correct operation and restriction. Check inches of |
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| water column closing pressure of high pressure switch on heat call, measure inches of water column of operat- |
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| ing pressure, inspect vent and combustion air inducer for correct operation and restriction. |
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273 | Watch Guard − Flame Fail in Run Mode | Check micro amperes of flame sensor in board diagnostics or field installed mode; clean or replace sensor. |
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| Measure voltage of neutral to ground for good unit ground. |
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274 | Watch Guard − Primary Limit Switch Open | Check why limit is tripping, over fired, low air flow. |
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275 | Watch Guard − Flame Out of Sequence. No | Shut off gas, check for gas valve leak. |
| Flame |
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276 | Watch Guard − Calibration Failure | Unable to perform pressure switch calibration. Check vent system and pressure switch wiring connections. |
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290 | Ignition Circuit Problem | Measure resistance of Hot Surface Ignition ignitor, replace if open or not within specification; otherwise replace |
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| control. |
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291 | Heat Airflow Restricted Below Min. | Check for dirty filter, unit air flow restriction, blower performance. |
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292 | Indoor Blower Motor Start Problem | Indoor blower motor unable to start (seized bearing, stuck wheel, etc.). Replace motor or wheel if assembly |
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| does not operate or meet performance. |
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294 | Inducer Motor Over current | Check combustion blower bearings, wiring, amps. Replace if does not operate or meets performance. |
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295 | Indoor Blower Over Temperature | Indoor blower motor over temperature (motor tripped on internal protector). Check motor bearings, amps; re- |
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| place if necessary. |
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310 | Discharge Air Sensor Problem | Compare outdoor sensor resistance to temperature/resistance charts in installation instructions. Replace sensor |
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| if necessary. |
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311 | Heat Rate Reduced to Match Airflow | Furnace blower in cutback mode due to restricted airflow. Check filter and ductwork. To clear, replace filter if |
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| needed or repair/add ductwork. |
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312 | Reduced Airflow − Indoor Blower Cutback | Restricted airflow − Indoor blower is running at a reduced CFM (Cutback Mode − The variable speed motor has |
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| pre−set speed and torque limiters to protect the motor from damage caused by operating out of its designed |
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| parameters (0 to 0.8" w.g. total external static pressure). Check filter and ductwork. To clear, replace filter if |
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| needed or repair/add ductwork. |
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| table continued on next page |
Page 33 | icomfortt Touch Screen 7−Day Programmable Thermostat |