Fig. 8—Service Label
A99233
SERVICE
G
R
Y
W
Com
HUM
TES
T
LE
D
LED CODE
STATUS
24V
11
12
13
14
21
22
23
24
31
33
34
*
9
8
6
5
32
1
4
7
COMPONENT TEST
NO PREVIOUS CODE - Stored status codes are erased when power
(115VAC or 24VAC) to control is interrupted or 48 hours after each fault is cleared.
BLOWER ON AFTER POWER UP (115VAC or 24 VAC) - Blower runs for 90
seconds, if unit is powered up during a call for heat (R-W closed).
LIMIT OR FLAME ROLL-OUT SWITCH LOCKOUT - Control will auto reset after
three hours. Reset switch or replace fuse link. Refer to #33.
IGNITION LOCKOUT - Control will auto-reset after three hours. Refer to #34.
GAS HEATING LOCKOUT - Control will NOT auto reset.
Check for: - Mis-wired gas valve -Defective control (Valve relay)
ABNORMAL FLAME-PROVING SIGNAL - Flame is proved while gas valve is
de-energized. Inducer will run until fault is cleared.
Check for: - Leaky gas valve - Stuck-open gas valve
PRESSURE SWITCH DID NOT OPEN - Check for:
- Obstructed pressure tubing. - Pressure switch stuck closed.
SECONDARY VOLTAGE FUSE IS OPEN
Check for: - Short circuit in secondary voltage (24VAC) wiring.
PRESSURE, DRAFT SAFEGUARD, AUX-LIMIT SWITCH (when used*) OR BLOCKED
VENT SWITCH (when used) DID NOT CLOSE OR REOPENED
(DOWNFLOW ONLY*) If open longer than five minutes, inducer shuts off for 15
minutes before retry. Check for:
- Proper vent sizing
- Low inducer voltage (115VAC)
- Defective inducer motor
- Defective Blower motor or capacitor
- Restricted vent
- Defective pressure switch
- Excessive wind
- Inadequate combustion air supply
- Disconnected or obstructed pressure tubing
If it opens after trial for ignition period, blower will come on for 90 second
recycle delay.
LIMIT OR FLAME ROLL-OUT SWITCH IS OPEN - If open longer than three
minutes, code changes to #13. Flame roll-out switch requires manual reset.
Check for: - Defective blower motor or capacitor.
- Dirty filter or restricted duct system.
- Loose blower wheel.
- Defective switch or connections.
- Inadequate combustion air supply (Flame Roll-out Switch or fuse link open).
- Open Flame Roll-out Switch, or fuse link. Manual reset or replace.
IGNITION PROVING FAILURE - Control will try three more times before
lockout #14 occurs. If flame signal lost after trial for ignition period, blower
will come on for 90 second recycle delay. Check for:
- Oxide buildup on flame sensor (clean with fine steel wool).
- Proper flame sense microamps (.5 microamps D.C. min., 4.0 - 6.0 nominal).
- Gas valve defective or gas valve turned off.
- Defective Hot Surface Ignitor
- Manual valve shut-off.
- Low inlet gas pressure.
- Control ground continuity
- Green wire MUST be connected to furnace sheet metal.
- Inadequate flame carryover or rough ignition.
- Flame sensor must be ungrounded.
To initiate the component test sequence, shut OFF the room thermostat or
disconnect the "R" thermostat lead. Briefly short the TEST terminal to the "Com
24V" terminal. Status LED will flash code and then turn ON the inducer motor.
The inducer motor will run for the entire component test. The hot surface ignitor,
blower motor-heat speed, and blower motor-cool speed will be turned ON for
10-15 seconds each. Gas Valve and Humidifier will not be turned on.
If status code recall is needed, do not remove power or blower door. Briefly remove and then
reconnect one main limit wire to display stored status code.
CONTINUOUS OFF - Check for 115VAC at L1 and L2, and 24VAC at SEC-1 and
SEC-2.
CONTINUOUS ON - Control has 24VAC power.
RAPID FLASHING - Line voltage (115VAC) polarity reversed. If twinned, refer
to twinning kit instructions.
EACH OF THE FOLLOWING STATUS CODES IS A TWO DIGIT NUMBER WITH THE FIRST
DIGIT DETERMINED BY THE NUMBER OF SHORT FLASHES AND THE SECOND DIGIT BY
THE NUMBER OF LONG FLASHES.
320615-102 REV. K (LIT)
8
