Precedent Symbio Modulating Gas Heat Error codes
The following diagnostics are available through direct data monitoring from the Modbus controlled gas heat ignition module (VB1285) or through data monitoring.
1285 Control: 3-Character Status Display Codes
| Display Code | Code Type | Description | Additional comments and 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 | |
| Pur | Status | UP Mode: Burner state = Purge | |
| I 6 n | 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 I01 or I02) | 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 actuator position derated by >20% from FRI setting. |
| A04 | Alert | Limited Low Fire (due to Lost Flame Auto-Adaptation) | Flame loss at low fire results in an auto-adjustment that limits the burner turn down during the rest of the current call for heat. |
| 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 burner | 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 insufficient air --- lockout due to blocked vent. Includes air switch failure to open during pre-purge switch check. |
| 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 | 0s L/O | 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. |
| E11 | 10s L/O | 1287 Lockout (L/O) | 1287 L/O causes a 1285 L/O. Check 1287 control board LED state per the 1287 LED key below. |
| E13 | 10s L/O | Open fuse | |
| E18 | 10s L/O | 1287 Improper Flame | Unexpected flame, Split manifold burner. |
| E id | 10s L/O | Invalid I.D. Plug Installed |
VB1285 Ignition Module Display Code Callout
On power up
| H-A | Heatco Model Series |
| 600 | Gas Heating Input (600 MBH) |
| -10, -5 | 10:1 modulation turndown, 5:1 modulation turndown |
| nat, LP | Natural Gas, Propane Gas |
| 001 | Version of ID Chip |
| OFF | Standby Mode - awaiting call for heat or increase in firing rate demand |
| Pur | Purge - 30 second purge period |
| IGn | Ignition sequence - 6 second trial for ignition and flame signal proving |
| HEA | Warm up - 10 second warm up period (ignores firing rate demand) |
| Run | Normal run operation |
During normal run operation the display will cycle through multiple codes
| Run | Normal run operation |
| Fr= | Firing rate percentage |
| 100 | Numerical value firing rate percentage (numerical values will change) |
| AIr | Inducer fan pressure |
| 1.80 | Numerical value of inducer pressure (numerical values will change) |
During abnormal operation the display will cycle through multiple codes
| A01 | Alert Code (There are nine different alert functions) |
| Fr= | Firing rate percentage |
| 100 | Numerical value firing rate percentage (numerical values will change) |
| AIr | Inducer fan pressure |
| 1.80 | Numerical value of inducer pressure (numerical values will change) |
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WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.