SERVICING
60
LED
Fla she s/S ta tus
S yste m Condition
Off
Internal Control Fault, M icro Controller
Detected Hardware Failure, or Gas V alve
Detected E nergized W hen it Should be
De-energized
1
Loc kout Due to E xcess ive Retries
2
Pressure S witch S tuc k Clos ed
3
Pressure S witch S tuc k Open
4
Open High Tem perature Lim it
5
Flam e Present Outs ide the Flam e
Detect M ode
6
Com pressor S hort Cyc le Delay A ctive
7
Lim it Opened Five Tim es within the
Sam e Call for Heat
8
Indoor Therm ostat/Outdoor Therm os tat
is Open
9
Pressure S witch/Loss of Charge S witch
is Open
S teady ON
Norm al
Red LED Fault Codes
LED
Flashes/Status
Flame Condition
2
Flame Present Outside the Flame Detect
Mode
1
Low Flame Signal Current
Steady ON
Normal Flame
OFF
No Flame Present
Amber LED Flame Status Codes
NOTE:
The flash rate is 0.25 seconds on, 0.25 seconds
off, with a 2-second pause between codes.
NORMAL SEQUENCE OF OPERATION
(DSI Direct Spark Ignition System)
PCBAG123 Board
1. Thermostat calls for heat by energizing "W". The control
checks the pressure switch for open condition. If the
pressure switch is closed the control will flash code "3"
and wait for the pressure switch to open.
2. The induced draft motor is energized and the control
flashes code "2" and waits for the pressure switch to
close. Once the pressure switch is closed, the LED stops
flashing and the control begins timing the 15 second pre-
purge.
3
2
1
6
5
4
9
8
7
12
11
10
L2
L2
L2
L2
COOL
HEAT
UNUSED
L1
L1
D1
FS
D
ia
g
n
o
s
tic
L
E
D
Blower Off Delay Settings
Transformer
speed up
DSI Control Board
3. The control energizes the spark igniter and gas valve for
7 seconds. If flame is established, the control goes into
a 30 second heat on delay.
4. The indoor blower is energized at the heat speed after a
30 second on delay.
5. The control monitors the safety circuit inputs, flame, and
thermostat during operation.
6. When the thermostat is satisfied, the gas valve is de-
energized and the induced draft blower remains on for a
29 second post purge. The indoor blower remains on for
the selected heat blower off delay (90, 120, or 150
seconds). Indoor blower off timing begins when thermo-
stat call for heat ends.
Testing Direct Spark Ignition (DSI) systems
Thermostat calling for heat (15 second prepurge time and 7
second trial for ignition).
1. Check for 230 VAC from L1 terminal of control module to
L2. No voltage - check wire connections, continuity, etc.
2. Check for 24 VAC at "R" to "C" thermostat terminals.
a.
No voltage - check 3 amp automotive type fuse on
control board. A blown fuse would indicate a short
in the 24 VAC circuit (thermostat or limit circuit).
b.
Voltage Present - check limit, auxiliary limit and
rollout (S-300, S-301 and S-302). If limit, auxiliary
limit and rollout are closed, then check for 24 VAC
at the gas valve terminals.
No 24 VAC at gas valve - replace Control board.
