8
ATH15-501.0 (
Supplement to ATH15-500.10
)
Table 8.1 - Primary Furnace Control Board (VB1285) Error Codes
(Applies to all units with Gas Heat Option furnace model number Digit 11= 6, 9, A, B, C, or D)
FURNACE CONTROLLER ERROR CODES
To clear furnace control board error codes, refer to the section “Clearing Furnace Control Board Error Codes” on page 7.
Display
Code
Code
Type
Description
Additional Notes
888
10s L/O Board Failure
(Up to 10 sec @ power up)
Verify 24 VAC signal input at connector J6.
Off
Status
UP Mode: Burner state = Off
Normal Operation
Pur
Status UP Mode: Burner state = Purge
Ign
Status UP Mode: Burner state = Ignition
HEA
Status UP Mode: Burner state = Warmup
Run
Status UP Mode: Burner state = Run
rEt
Status UP Mode: Burner state = Retry
(with
A01
or
A02
)
Retry delay following either a failed ignition or a flame loss.
A01
Alert Failed ignition attempt
A02
Alert Lost Flame
Ignition was successful but then flame disappeared.
A03
Alert
Insufficient Combustion Air
Blocked vent with modulator position de-rated by >20% from
Fire Rate Input (demand) setting.
A04
Alert Limited Low Fire (due to Lost Flame Auto-
Adaptation)
Flame loss at low fire results in an auto-adjustment limit of
the burner turndown by adjusting the minimum modulation
voltage during the rest of the current cycle or until a CPU
reset.
A05
Alert Weak Flame Signal
Flame presence signal of less than 1.5μA indicates an aged
flame rod.
A07
Alert Loss of Inducer Motor Control
The Air Pressure is not modulating down at minimum
inducer drive.
A08
Alert Air Sensor Null Pressure Check out-of-tolerance
The Air Pressure sensor zero reading appears to be out-of-
tolerance.
A11
Alert Failed Ignition – Split Manifold
Failed Ignition, Split manifold burner, retries exhausted.
A15
Alert Weak Flame Signal – split manifold
Weak Flame Signal, one or more split-manifold staged
burners.
E01
1hr L/O Failed Ignition
Four failed ignition attempts have occurred.
E02
10s L/O Primary Limit Failure
Verify Primary Limit input at connector J8 and fuse at F1.
E03
10s L/O Modulation Valve Failure
The Valve Actuator did not reach a Park or Full On position.
E04
30s L/O Air Sensor Failure -
Pressure Reading Low
Includes air switch failure to open during pre-purge switch
check, includes
insufficient air lockout due to blocked vent.
E05
30s L/O Air Sensor Failure -
Pressure Reading High
Includes air switch failure to close during pre-purge switch
check.
E08
10s L/O Improper Flame
E09
No R-W Enable
An R-W open circuit is preventing the control from operating
on a non-zero Firing Rate Demand or Firing Rate Input.
E13
10s L/O Open Fuse
EId
10s L/O Invalid I.D. Plug Installed
Furnace Controller Error Codes
Tables 8.1 through 9.2 are for the furnace controllers on gas
heat option furnace model digit 11= 6, 9, A, B, C, or D). Refer
to the Troubleshooting section in the model MPR Installation
and Service Manual, Literature ATH15-500.10 for a listing of
Possible Causes and Remedies for the full unit.
