5566228-BIM-A-0818
62
Johnson Controls Ducted Systems
Table 31: 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 Smart Equipment 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 Smart Equipment 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