Brand: Allied Air Enterprises
Category: Furnace
Document Type:
Language: EN
Manual for A93UH1E & 92G1UHE - Troubleshooting and error codes + PDF Download
Uploaded: April 1, 2025, 12:48 a.m.
Warranty Summary
See manual for manufacturer's limited equipment warranty details.
Heating Sequence of Operation:
- Thermostat calls for heat, combustion air inducer starts.
- Combustion air pressure switch proves blower operation.
- 15 second pre-purge, hot surface ignitor energizes.
- 20 second ignitor warm-up, gas valve solenoid opens.
- 4-second "Trial for Ignition" period begins.
- Gas ignites, flame sensor proves flame, combustion continues.
- If flame not detected, ignition control repeats ignition trials before lockout.
Troubleshooting and error codes
| Red LED Flash Code | Diagnostic Codes / Status of Furnace |
|---|---|
| Off | No power to control or control hardware fault detected |
| Heartbeat¹ | Normal operation - idle, continuous fan, cool |
| Continuous Rapid Flash | Call for heat / burner operation |
| 1 Flash | Reverse line voltage polarity |
| 2 Flashes | Improper earth ground |
| 3 Flashes | Burner failed to light, or lost flame during heat demand |
| 4 Flashes | Low flame signal - check flame sensor |
| 5 Flashes | Watchguard - burner failed to light, exceeded maximum number of retries or recycles |
| 6 Flashes | Not used |
| 7 Flashes | Primary or Secondary limit open or watchguard mode - limit switch open longer than 3 minutes |
| 8 Flashes | Rollout switch open |
| 9 Flashes | Pressure switch failed to close or opened during heat demand |
| 10 Flashes | Watchguard - Pressure switch opened 5 times during one heat demand |
| 11 Flashes | Pressure switch stuck closed prior to activation of combustion air inducer |
| 12 Flashes | Flame sensed without gas valve energized |
| 13 Flashes | Low line voltage |
| Off | No power to control or control hardware fault detected |
| On | Board Fault Detected |
| Fast Heartbeat³ | Call for Heat / Burner Operation |
| Slow Heartbeat¹ | Normal Operation - Idle, Continuous Fan, or Cool |
| 1 Flash² | Reverse Line Voltage Polarity or Phasing of 120V power |
| 2 Flashes² | Improper earth ground |
| 3 Flashes² | Burner failed to light, or lost flame during heat demand |
| 4 Flashes² | Low flame signal - check flame sensor |
| 5 Flashes² | Watchguard - burner failed to light, exceeded maximum number of retries/recycles, 1 hour lockout |
| 6 Flashes² | Not used |
| 7 Flashes² | Primary or Secondary limit switch open or Watchguard mode – Limit Switch open longer than 3 minutes |
| 8 Flashes² | Rollout switch open |
| 9 Flashes² | Pressure switch failed to close or opened during heat demand |
| 10 Flashes² | Watchguard - Pressure switch opened 5 times during one heat demand |
| 11 Flashes² | Pressure switch stuck closed prior to activation of combustion air inducer |
| 12 Flashes² | Flame sensed without gas valve energized |
| 13 Flashes² | Low line voltage |