22
Flames should be stable, soft and blue (dust may cause orange tips
but must not be yellow). The flames must extend directly outward
from the burner without curling, floating or lifting off.
BURNER FLAME
T
O
AVOID
PERSONAL
INJURY
OR
DEATH
DUE
TO
ELECTRIC
SHOCK
,
DO
NOT
REMOVE
ANY
INTERNAL
COMPARTMENT
COVERS
OR
ATTEMPT
ANY
ADJUSTMENT
. C
ONTACT
A
QUALIFIED
SERVICER
AT
ONCE
IF
AN
ABNORMAL
FLAME
SHOULD
DEVELOP
.
WARNING
At least once a year, prior to or during the heating season, make a
visual check of the burner flames.
NOTE: This will involve removing and reinstalling the heat
exchanger door on the unit, which is held by two screws. If you are
uncertain about your ability to do this, contact a qualified servicer.
If a strong wind is blowing, it may alter the airflow pattern within
the unit enough that an inspection of the burner flames is not
possible.
F
UNCTIONAL
P
ARTS
Refer to the unit Parts Catalog for a list of functional parts. Parts
are available from your distributor.
TROUBLESHOOTING
I
GNITION
C
ONTROL
E
RROR
C
ODES
The following presents probable causes of questionable unit op-
eration. Refer to Diagnostic Indicator Chart for an interpretation
of the signal and to this section for an explanation.
Remove the control box access panel and note the number of di-
agnostic LED flashes. Refer to Diagnostic Indicator Chart for an
interpretation of the signal and to this section for an explanation.
Internal Control Failure
If the integrated ignition control in this unit encounters an inter-
nal fault, it will go into a “hard” lockout and turn off the diagnostic
LED. If diagnostic LED indicates an internal fault, check power sup-
ply to unit for proper voltage, check all fuses, circuit breakers and
wiring. Disconnect electric power for five seconds. If LED remains
off after restoring power, replace control.
A
BNORMAL
O
PERATION
- H
EATING
C
ODES
External Lockout (1 FLASH CODE)
An external lockout occurs if the integrated ignition control deter-
mines that a measurable combustion cannot be established within
three (3) consecutive ignition attempts. If flame is not established
within the seven (7) second trial for ignition, the gas valve is
deenergized, 15 second inter-purge cycle is completed, and igni-
tion is reattempted. The control will repeat this routine three times
if a measurable combustion is not established. The control will
then shut off the induced draft blower and go into a lockout state.
If flame is established but lost, the control will energize the circu-
lator blower at the heat speed and then begin a new ignition se-
quence. If flame is established then lost on subsequent attempts,
the control will recycle for four (4) consecutive ignition attempts
(five attempts total) before locking out.
The diagnostic fault code is 1 flash for a lockout due to failed igni-
tion attempts or flame dropouts. The integrated control will auto-
matically reset after one hour, or it can be reset by removing the
thermostat signal or disconnecting the electrical power supply for
over five seconds. If the diagnostic LED indicates an external lock-
out, perform the following checks:
• Check the supply and manifold pressures
• Check the gas orifices for debris
• Check gas valve for proper operation
• Check secondary limit
A dirty filter, excessive duct static, insufficient air flow,
a faulty limit, or a failed circulator blower can cause
this limit to open. Check filters, total external duct
static, circulator blower motor, blower motor speed tap
(see wiring diagram), and limit. An interruption in
electrical power during a heating cycle may also cause
the auxiliary limit to open. The automatic reset
secondary limit is located on top of the circulator
blower assembly.
• Check rollout limit
If the burner flames are not properly drawn into the
heat exchanger, the flame rollout protection device will
open. Possible causes are restricted or blocked flue
passages, blocked or cracked heat exchanger, a failed
induced draft blower, or insufficient combustion air.
The rollout protection device is a manual reset limit
located on the burner bracket. The cause of the flame
rollout must be determined and corrected before
resetting the limit.
Summary of Contents for DCG Series
Page 29: ...27 APPENDIX D WIRING DIAGRAMS...
