Modine Manufacturing Atherion MPR Installation And Service Manual Supplement page 8

FURNACE CONTROLLER ERROR CODES
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.
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)
Display Code
Code Type
888 10s L/O Board Failure (Up to 10 sec @ power up)
Off Status UP Mode: Burner state = Off
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)
A01 Alert Failed ignition attempt
A02 Alert Lost Flame
A03 Alert Insufficient Combustion Air
Limited Low Fire (due to Lost Flame Auto-
A04 Alert
Adaptation)
A05 Alert Weak Flame Signal
A07 Alert Loss of Inducer Motor Control
A08 Alert Air Sensor Null Pressure Check out-of-tolerance
A11 Alert Failed Ignition – Split Manifold
A15 Alert Weak Flame Signal – split manifold
E01 1hr L/O Failed Ignition
E02 10s L/O Primary Limit Failure
E03 10s L/O Modulation Valve Failure
E04 30s L/O Air Sensor Failure - Pressure Reading Low
E05 30s L/O Air Sensor Failure - Pressure Reading High
E08 10s L/O Improper Flame
E09 No R-W Enable
E13 10s L/O Open Fuse
EId 10s L/O Invalid I.D. Plug Installed
To clear furnace control board error codes, refer to the section "Clearing Furnace Control Board Error Codes" on page 7.

8
Description
ATH15-501.0 (Supplement to ATH15-500.10)
Additional Notes
Verify 24 VAC signal input at connector J6.
Normal Operation
Retry delay following either a failed ignition or a flame loss.
Ignition was successful but then flame disappeared.
Blocked vent with modulator position de-rated by >20% from
Fire Rate Input (demand) setting.
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.
Flame presence signal of less than 1.5μA indicates an aged
flame rod.
The Air Pressure is not modulating down at minimum
inducer drive.
The Air Pressure sensor zero reading appears to be out-of-
tolerance.
Failed Ignition, Split manifold burner, retries exhausted.
Weak Flame Signal, one or more split-manifold staged
burners.
Four failed ignition attempts have occurred.
Verify Primary Limit input at connector J8 and fuse at F1.
The Valve Actuator did not reach a Park or Full On position.
Includes air switch failure to open during pre-purge switch
check, includes
insufficient air lockout due to blocked vent.
Includes air switch failure to close during pre-purge switch
check.
An R-W open circuit is preventing the control from operating
on a non-zero Firing Rate Demand or Firing Rate Input.