45
Communicating Furnace
INTEGRATED FURNACE CONTROL
DUAL SEVEN-SEGMENT DISPLAY
3. When the furnace is in a heat or cool blower off
elay, the display should be “0”.
A standard operating code (with fault level “0”) shall
be displayed steady-on.
When displaying a fault code, it shall be flashed
and not be displayed steady-on. It shall be flashed
on for one second, then off for ½ second then on
again. Cycle repeats until the fault is cleared. Each
fault is flashed (displayed) a minimum of two times
even if the fault condition has cleared before the
fault can be displayed twice.
Dual Faults Displayed
Normally only one fault or status character is displayed at
the Seven-segment display at any given time. Exceptions
for some dual faults are noted below.
Sequence of display:
A. The first fault will be displayed for one second
B. The upper-most horizontal segment of the right
seven-segment display is energized for ½ second
C. The second fault is displayed for one second
D. The upper-most horizontal segment of the right
seven-segment display is energized for ½ again.
This cycle repeats until one or both faults are gone or oth-
erwise as noted below:
1. When both low pressure switch and high pressure
switch are open and both should be closed fault
codes
“45”
and
“57”
will be displayed alternately
as described above (A-D).
2. When a failed ignition has occurred four times in a
row, the control enters one-hour lockout and fault
codes
“10”
and
“11”
will be displayed alternately
as described above (A-D).
3. When flame is lost five times in a row, the control
enters one-hour lockout and fault codes “
10
” and
“13”
will be displayed alternately as described
above (A-D).
4. When both the low pressure switch and high pres-
sure switch are closed and both should be open (as
in during the pressure switch proving period). In
this case fault codes
“44”
and
“55
” will be dis-
played alternately as described above (A-D).
5. When the high pressure switch is open and the de-
mand from the thermostat is set to 100% heat. . . In
this case the operation code “
h
” (for low heat) and
the fault code
“57”
(open high pressure switch) will
be displayed alternately.
6. While the control is in one-hour lockout due to an
unexpected flame, the fault codes
“14”
(unex-
pected flame) and
“10”
(soft lockout) will be dis-
played alternately as described above (A-D).
NOTE:
Fault code 10 will not be displayed until
after fault has cleared.
7. While the control has entered a one-hour lockout
after declaring a dead blower after the main limit
control has been open for more than 150 seconds,
the fault codes
“61”
(Non-operational blower) and
“10”
(soft lockout) will be displayed alternately as
described above (A-D). Note: the dead blower fault
and associated one-hour lockout will occur up to
four times in one heat call. Upon declaring this fault
for the fourth time in one heat call, the control will
enter hard lockout.
8. When the main limit has been open during a gas
heat call for more than 150 seconds and has not
yet re-closed, the fault codes
“61”
(Non-operational
blower) and
“22”
(open limit) will be displayed al-
ternately as described above (A-D) until the limit re-
closes.
9. When IFC is in soft lockout and fault
“93”
is active,
the fault code
“93”
is to be displayed alternately
with the fault code
“10”
.
10. When gas valve is open, flame is sensed and IFC
detects a fault condition which will not prevent gas
heating operation from continuing (like fault “
57
”,
“12”
,
“66”
,…) , IFC will display the operation code
“h”
or
“H”
alternately with the active fault code.
