1133391-YIM-A-1014
Johnson Controls Unitary Products
65
Table 29: Flash Codes for the Gas Heat Ignition Control Board
Flash Code
Description
Technician Corrective Action
Heartbeat
Normal Operation - no staus or error information
currently needs to be displayed
Steady Off
No Power to Control - 24v AC is not present to the
control's 24VAC and C terminals.
Alternately: The control has catastrophic damage that will
not allow the LED display - It is likely that there will be
visible physical evidence of the damage
Verify line voltage is present at the primary of the 75VA transformer, verify 24v
AC is present at the secondary of the 75VA transformer. Verify 24v AC is
present from the Simplicity Lite control's C to SD terminals indicating the 3.2A
control circuit breaker and phase monitor contacts are closed. Verify 24v AC is
present from the ignition control's C to 24VAC terminals indicating the
Simplicity Lite to Ignition control wiring is intact.
Steady On
The Control's Microprocessor Has Not Passed its Self-
check
Cycle power to the control to eliminate the possibility that transient voltage
conditions such as surges, brownouts, etc. have not created a false indication.
If the steady on LED indication repeats, the control will need to be replaced and
potential causes for failure, such as excessive voltage, RF interference, etc.
should be investigated.
2 Flashes
The Induced Draft Pressure Switch is Stuck Closed - 24v
AC is received to the control's PS terminal at the same
time as 24v AC to initiate heating operation is received at
the control's W1 terminal
Verify that the induced draft pressure switch contacts are not stuck or welded
closed. Verify that the ignition control's INDUCER contacts are not stuck or
welded closed causing the induced draft motor to run continuously. Verify that
the wiring from the ignition control's W1 terminal through the induced draft
pressure switch and rollout switch to the ignition control's PS terminal is not
shorted.
3 Flashes
The Induced Draft Pressure Switch Did Not Close - 24v
AC was not received to the control's PS terminal within 5
seconds of the ignition control energizing the induced
draft motor or 24v AC was later lost to the control's PS
terminal while the ignition control energized the induced
draft motor
Verify that the induced draft motor is operable, the ignition control's INDUCER
contacts are not open, the induced draft blower wheel is intact and there are no
blockages in the combustion air / induced draft path. Verify that the induced
draft pressure switch sensing tubing is intact. With an incline manometer, digital
manometer or Magnehelic® gauge teed into the pressure switch sensing line
verify that the negative pressure exceeds the setting listed on the induced draft
pressure switch label and the switch's contacts correctly close at the setting
listed
4 Flashes
Open Limit - 24v AC has been lost to the control's L
terminal
Verify proper gas manifold pressure. Correct the inadequate indoor airflow
condition. Verify filters, indoor coil and blower wheel are clean. Verify that the
blower belt is properly maintained and adjusted; the blower contactor and
motor are operable and wheel has the correct rotation. Verify that the ducting is
not restrictive. Verify indoor air volume is at least the minimum required for the
heat section by measuring the indoor coil pressure drop and comparing the
reading to the chart in the Installation Manual. Verify heating mode blower on/
off delays are proper for the heat type and provide adequate heat section
cooling at the termination of the heating cycle. Verify wiring for main and
auxiliary limits is intact
5 Flashes
Flame has been sensed when the MV1 output is off, or
24v AC is present at the MV1 output without 24v AC to
the W1 input, or 24v AC is present at the MV2 output
without 24v AC at the MV1 output
Verify that the gas valve is not slow to shut off, leaks by or otherwise does not
completely shut off gas flow when de-energized. Verify gas valve wiring to the
control's MV1 and MV2 terminals is intact and not shorted in a manner that
would improperly allow 24v AC from another circuit to be applied to the
control's MV1 or MV2 terminals. Verify the control's contacts for MV1 and MV2
outputs are not shorted.
6 Flashes
Ignition lockout - A flame signal of 1.0
μ
a or greater could
not be established in 3 attempts for ignition at the
initiation of the heating cycle / or / the flame signal has
dropped below 1.0
μ
a 5 times during the heating cycle
Verify that combustion air openings are without blockages and that the unit has
proper clearance to the structure and adjacent units .Verify that the burners are
clean and without blockages that could interfere with gas flow. Verify that the
ignitor sparks with an
≈
1/8" gap to the crossover area of the left burner. Verify
that the flame sensor is intact and positioned with an
≈
1/8" gap to the right
burner. Verify that the gas lines have been purged of air and proper gas inlet
pressure. Verify that the gas valve is opening and adjusted to provide proper
manifold pressure. Verify that the wiring to the gas valve is intact. Verify that
there is no wind, rain or snow entering the heat compartment to interfere with
ignition or the burners. Verify that there are no conditioned air leaks or heat
exchanger breaches to interfere with ignition or the burners
