7-Day Programmable
iComfort Wi‐Fi
®
Flex Thermostat
33
Table 2. 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
347
Critical
(Furnace / Air Handler / Equipment
Interface Module) The “Y1” relay on
the
(furnace or airhandler)
has failed.
Either the pilot relay contacts did not
close or the relay coil did not ener
gize.
Operation stopped. Y1 relay / Stage 1 failed. (Pilot relay contacts did not close
or
the relay coil did not energize; no input back to IFC chip). Critical Alert.
Cleared after reset and Y1 input sensed.
348
Critical
(Furnace / Air Handler) The “Y2” relay
on the
(furnace or airhandler)
has
failed. Either the pilot relay contacts
did not close or the relay coil did not
energize.
Y2 relay / Stage 2 failed. (Pilot relay contacts did not close or the relay coil did
not energize; no input back to IFC chip). Critical Alert. Cleared after reset and
Y1 input sensed.
380
Moderate
/ Critical
(Equipment Interface Module) Inter
lock relay failure (IFC or AHC mode
only)
Interlock relay is energized, but input is not sensed after 3 seconds. There will
be no heating or cooling due to this error. Deenergize interlock relay and ener
gize after 5 minutes if demand is still present.
381
Moderate
/ Critical
(Equipment Interface Module) Inter
lock relay stuck (IFC or AHC modes
only)
Interlock relay continuously sensed (with relay off). No heating and cooling
operations. Alarm clears 30 seconds after fault clears.
382
Moderate
(Equipment Interface Module) Relay
W1 failure (IFC and AHC modes only)
W1 relay energized, but input is not sensed after three seconds.
420
Critical
(Outdoor Unit) The “W” output termin
al on the outdoor unit is not wired cor
rectly
Defrost cycle lasts longer than 20 minutes. Check heat pump operation.
Cleared
when W1 signal is removed. Applicable only in communicating mode with
noncommunicating heat pump.
594
Moderate
/ Critical
(Equipment Interface Module) Precoil
discharge air temperature sensor
problem (DFM mode only). Advances
from moderate to critical after ten (10)
minutes.
Interlock relay energized, but input not sensed after 3 seconds. No heating and
cooling operations. Deenergize interlock relay and reenergized 5 minutes
later if demand is still present. Alarm clears 5 minutes after fault clears.