iComfort
Wi‐Fi
®
7-Day Programmable Communicating Thermostat
25
Table 1. Alert Codes and Troubleshooting
Critical alerts are displayed on Home (user) screen, in the Homeowner alert button, and in
the Installer alert button. Minor and Moderate alerts are found only in the Installer alert
button.
Alert
Code
Steps to clear
Alert Text
Priority
224
Critical
(Furnace) The furnace low pressure switch
is stuck closed.
Check operation of low pressure switch to see if it is stuck closed for longer than 150
seconds during a heat call . Measure operating pressure (inches w.c.). Inspect vent and
combustion air inducer for correct operation and restriction. The alarm/fault clears after the
issue is corrected.
225
Critical
(Furnace) The furnace high pressure switch
is failing to close.
Check pressure (inches w.c.) of high pressure switch closing during a heat call. Measure
operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct
operation and restriction. The alarm/fault clears after the issue is corrected.
226
Critical
(Furnace) The furnace high pressure switch
is stuck closed.
Check operation of high pressure switch closing during a heat call. Measure operating
pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and
restriction. The alarm/fault clears after the issue is corrected.
227
Moderate
(Furnace) The furnace low pressure switch
is open in run mode.
Check pressure (inches w.c.) of low pressure switch closing during a heat call. Measure
operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct
operation and restriction. The alarm/fault clears after the issue is corrected.
228
Moderate
(Furnace) The furnace control is not able to
calibrate the pressure switch.
Unable to perform pressure switch calibration. Check vent system and pressure
switch wiring connections. Check the drain trap for blockage. The alarm/fault clears after a
successful calibration.
229
Minor
(Furnace) The furnace control has switched
to high fire ignition because the low fire pres
sure switch did not close in the allowed time.
IFC switched to high fire ignition because low fire pressure switch did not close in allowed
time. No action is needed.
240
Moderate
(Furnace) The furnace flame current is low.
Check microamperes of the flame sensor using thermostat diagnostics. Clean or replace
the flame sensor. Measure voltage of neutral to ground to ensure good unit ground. The
alarm clears after a proper microamp reading has been sensed.
241
Critical
(Furnace) The furnace flame is going out
while the furnace is heating.
Shut off gas. Check for a gas valve leak. Replace the gas valve if needed. The alarm/fault
will clear when a heat call ends successfully.
250
Moderate
(Furnace) The furnace primary limit switch is
open.
Check for proper firing rate on furnace. Ensure there is no blockage in the furnace and the
duct work. Check for proper air flow. If limit switch is not closed within 3 minutes, the unit
will go into 1hour Watchguard mode. The alarm/fault will clear when a heat call ends
successfully.
252
Moderate
(Furnace) The furnace discharge airtemper
ature is high.
Check temperature rise, air flow and input rate. Check for dirty filters. The alarm/fault will
clear when a heat call ends successfully.
270
Critical
(Furnace) The furnace is in Watchguard
mode. The furnace igniter cannot turn on the
flame.
This is a five strike condition during a single demand. Check for proper gas flow. Ensure
that igniter is lighting burner. Check flame sensor current. Check for dirty filters. The alarm/
fault will clear on successful ignition.
