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