STEP
ACTION
YES
NO
GO TO
12
Does a different status code flash?
7
13
13
Disconnect the jumper wire across R and W/W1 thermostat
terminals and wait until the blower stops.
14
14
Jumper R, W/W1, and W2 thermostat terminals on the vari-
able speed furnace control.
15
15
Does status code 21 start flashing when the high heat pres-
sure switch HPS makes?
16
17
16
The BLUE and GREEN wires to gas valve GV are re-
versed.
4
17
Cycle the furnace several times to check for intermittent
operation.
18
18
Does status code 21 ever flash?
11
19
19
Go to page number indicated in Index for CLEANUP AND
START-UP INSTRUCTIONS. If the problem persists on an
intermittent basis, replace the variable speed furnace con-
trol. If problem still persists on an intermittent basis after
replacing the variable speed furnace control, contact your
distributor.
INDEX
Status Code 22
ABNORMAL FLAME-PROVING SIGNAL - This status code indicates the flame signal was sensed while gas valve GV was de-energized.
The inducer will run until the fault is cleared.
STEP
ACTION
YES
NO
GO TO
1
Turn off gas to the furnace by shutting off the external
manual shut-off valve.
2
2
Does status code 22 stop flashing?
3
4
3
Replace the gas valve.
5
4
Replace the variable speed furnace control.
5
5
Go to page number indicated in Index for CLEANUP AND
START-UP INSTRUCTIONS.
INDEX
Status Code 23
PRESSURE SWITCH DID NOT OPEN - This status code indicates the low or high heat pressure switch LPS or HPS is made when a call for
heat is initiated. The variable speed furnace control will flash status code 23 until the switch opens, then cycle begins.
STEP
ACTION
YES
NO
GO TO
1
Turn power off, remove blower access panel, and discon-
nect R thermostat lead.
2
2
Turn power on and depress door switch. Use a piece of
tape to hold switch closed.
3
3
Jumper R and W/W1 thermostat terminals.
4
4
Does status code 23 flash?
8
5
5
Does a different status code flash?
6
7
6
Go to page number indicated in the Index for the section
covering the status code.
INDEX
7
Go to page number indicated in Index for CLEANUP AND
START-UP INSTRUCTIONS.
INDEX
8
Is the inducer motor ON?
21
9
9
Is 24-vac across ORANGE wire on the low heat pressure
switch LPS and C
OM
-24V on variable speed furnace con-
trol?
16
10
10
Is 24-vac across connector terminal PL1-4 and C
OM
-24V on
variable speed furnace control?
11
13
11
The main harness is miswired.
7
12
Rewire low heat pressure switch LPS per the wiring dia-
gram.
7
13
Is 24-vac across BROWN wire on the high heat pressure
switch HPS and C
OM
-24V on variable speed furnace con-
trol?
18
14
14
Is 24-vac across connector terminal PL1-3 and C
OM
-24V on
variable speed furnace control?
11
15
15
Replace variable speed furnace control.
7
16
Is the low heat pressure switch LPS wired correctly?
17
12
17