Status Code 34
IGNITION-PROVING FAULT - This status code indicates flame was not sensed during trial for ignition period. The control will repeat ignition
sequence 3 more times before going to status code 14 - IGNITION LOCKOUT. This status code can also indicate flame signal was lost during
steady-state operation.
STEP
ACTION
YES
NO
GO TO
1
Shut the power off, remove the blower access panel and
disconnect the R thermostat lead from the furnace control
board.
2
2
Turn the power on and depress the door switch. Use a
piece of tape to hold it closed.
3
3
Jumper the R and W/W1 thermostat terminals.
4
4
Observe the operation of the furnace through a heating
cycle.
5
5
Does status code 34 flash?
9
6
6
Does a different status code flash?
7
8
7
Go to page number indicated in the Index for the section
covering the status code.
INDEX
8
Go to page number indicated in Index for CLEANUP AND
START-UP INSTRUCTIONS.
INDEX
9
Turn off the power and disconnect the jumper across the R
and W/W1 thermostat terminals.
10
10
Turn the power on.
11
11
Check the hot surface igniter. To do this run a COMPO-
NENT TEST by putting setup switch SW1-6 in the ON posi-
tion. Does the igniter glow orange/white hot by the end of
the 15 second warm-up period?
16
12
12
Hook an AC voltmeter across PL2-3 and NEUTRAL-L2 on
the variable speed furnace control. Repeat the COMPO-
NENT TEST by turning setup switch SW1-6 OFF and then
back ON. Is 115-vac across PL2-3 and NEUTRAL-L2 dur-
ing the 15 second warm-up period?
14
13
13
Replace the variable speed furnace control.
8
14
Check continuity in harness and igniter. Replace failed com-
ponent.
15
15
Fix problem.
8
16
Put setup switch SW1-6 in the OFF position and jumper the
R and W/W1 thermostat terminals.
17
17
Is 24-vac across BLUE and GREEN/YELLOW wire to gas
valve GV?
21
18
18
Turn off the power.
19
19
Do you have continuity across the following connections?
- PL1-10 and the BLUE wire at the gas valve GV.
- PL1-5 and the GREEN/YELLOW wire at the gas valve
GV.
13
20
20
The BLUE or GREEN/YELLOW wire from the variable
speed furnace control to the gas valve GV is not making a
good connection. Repair the wire(s) or replace the harness.
8
21
Does the gas valve open and allow gas to flow?
24
22
22
Are all the manual gas cocks and the gas valve switch in
the ON position?
23
15
23
Replace gas valve.
8
24
Do the main burners ignite?
26
40
25
Check for the following:
- Inadequate flame carryover or rough ignition.
- Low inlet gas pressure.
- Air leakage around igniter bracket.
- Proper firing rate.
15
26
Do the main burners stay on longer than a few seconds?
36
40
27
Turn off the power and disconnect the jumpers across the
R, W/W1, and W2 thermostat terminals.
28
28
Connect a DC microampmeter in series with the flame sen-
sor wire.
29
29
Turn power on and jumper R, W/W1, and W2 thermostat
terminals.
30
30
Is the DC current below .5 microamps?
32
31
27