Fig. 60 – 3 Digit Display Flow Chart
Fig. 61 – Service Label Information
 
 
 
 
Flt
Last 7 faults that occured
CL
Cooling and Heat Pump Blower speed
CFn
Continuous Fan speed
Hod
Heat OFF delay
Cod
Cool OFF delay
Orientation upflow or downflow
inF
Ct
r5t
Dir
tnn
Twinning Main or Secondary
Program # and Software version
Component test
Ht
Heating Blower speed
Major Minor
Description
Description
Description
Major Minor
Major Minor
1
12
L1 polarity fault
W on at power up
Rapid flash 
LED
1
10
1
13
Limit Lockout - 
switch open longer 
than 3 minutes in
Main Limit circuit
1
33
A switch has opened in
the Main Limit circuit.
34
Ignition fault - during
four consecutive 
ignition trials.
2
After successful 
ignition (flame proven)
flame loss before 
heating blower on
delay.
After successful 
ignition (flame proven)
flame loss after heating
blower on delay.
3
45
46
1
Control failure – flame
circuit fault, memory 
mismatch or sequence
error.
2
Control failure – gas
valve relay will not
close.
3
1
Control failure 
–  EEPROM memory
issue.
For code 45, cycle power, if
code 45 repeats, replace 
control.
Momentary loss of
power
31
1
21
22
23
False flame
1
Open Main pressure
switch (LPS)
32
1
1
24
Fuse fault
1
27
1
2
3
1
Stuck closed Main
pressure switch
2
Stuck closed 
secondary pressure 
switch
1
14
Ignition Lockout  
after 4 consecutive 
ignition tries
2
Flame lost 3 times 
after 70s of heating
3
Lockout - 7 loss of  
flame events during
a heat request 
24VAC sensed on 
gas valve when 
shouldn’t be
25
No program info in 
micro, no heating 
operation.
Corrupted program 
file, reprogram 
control using service
app or super plug 
(supplied 
separately), no
heating operation.
1
2
Twinned units are 
not identical, 
program #'s do not
match. Ensure 
furnaces are
identical (same 
program #) 
when twinning. 
Main unit will not 
operate heating. 
3
4
5
6
7
Installer settings  
corrupted.Try  
reselecting installer 
settings, or reprogram 
control. Control will  
operate using default
installer settings.
Wrong program for 
control used - 
reprogram control so 
program matches  
control used. No 
heating operation.
Non-Condensing 
program detected in 
a Condensing model.
Program in super 
plug is missing, not 
recognized, or 
corrupted. Remove  
super plug then
retry. If still have 27
code, try a different
super plug. If still 
fails, replace control.
If program in furnace control 
is missing, not recognized, 
or corrupted. Reprogram 
Reprogram control with
correct program # as listed 
on the rating plate.Replace 
control if issue remains.
Main program invalid,
using backup program
to operate. Reprogram
control to correct 
issue. Control still
operates normally.
2
Open secondary 
pressure switch (HPS)
3
Secondary PS 
Lockout - failed to 
close secondary
PS after three trials
25
To initiate the component test sequence, the control must be in (idl) mode. No
thermostat demands (W, Y, G). Select component test (Ct) from menu select 
buttons to start the component test sequence. Once initiated the furnace control 
will perform the following sequence:
1. PUr- Inducer ON (remains ON for test).
2. HSI- After waiting 10s, HSI ON for 15 seconds.
3. Fn- After HSI, then Blower ON for 10 seconds.
4. End- After Blower, Inducer ON for 10 more 
    seconds.
    The test ends. 
COMPONENT TEST
MAIN MENU
All copyrighted materials used herein are the property of their
respective owners.
DISPLAY
DESCRIPTION
DISPLAY
DESCRIPTION
STATUS CODE TABLE
Scan QR code or reference troubleshooting guide in installation manual.
SYSTEM STATUS
CFn
bLr
Continuous Fan
Mode
Heat Pump Defrost
Mode
HPd
Cooling Mode
CL
Heating Mode
HT
Idle / Stand by
Mode
iDL
Active Status Code
Secondary Unit
Operating Blower 
during CFn, CL, 
or HT
##.#
MENU NAVIGATION
Scroll through main menu by pressing the MENU/SELECT button.
Press NEXT/OPTION button to view current setting (will flash on
display) and to scroll through setting options. Press 
MENU/SELECT button to save new setting and return to main 
menu. The display will flash to confirm setting selection before
returning to the main menu.
  The major status code is displayed in the first 2 digits of the display. The minor status   
  code is displayed in the third digit . The major status code is also displayed on the 
  LED indicator through the door with the first digit being the number of  short flashes 
  and the second digit being the number of long flashes.
Reset All Installer Settings to 
Factory Defaults
idL,Ht,…
Current System Status