| Heartbeat LED pattern on solid | The control is locked out and will auto-reset after 1 hour. | Reset power to clear the lockout. |
| Two LED flashes | Pressure switch didn’t open. | Obstructed pressure tubing; a pressure switch that’s stuck closed. |
| Three LED flashes | The low-pressure switch did not close or has reopened. | Proper vent sizing; air leak; restricted vent; clogged condensate drain; low input gas pressure; excessive wind; improper pressure switch wiring; water in vent piping; disconnected or obstructed pressure tubing. |
| Four LED flashes | Limit circuit fault. | Loose blower wheel; defective switch or connections; improper minimum- or maximum-heat gas input adjustment; dirty filter or restricted duct system; improper limit switch. |
| Five LED flashes | Abnormal flame-proving signal. | Leaky gas valve; stuck-open gas valve. |
| Six LED flashes | Ignition proving a failure. | Low inlet gas pressure; control ground continuity; gas valve defect; defective hot surface igniter; oxide buildup on the flame sensor; inadequate flame carryover; flame sensor mustn’t be grounded. |
| Seven LED flashes | Limit circuit lockout. | Control will auto-reset after 3 hours. Refer to status code #4. |
| Eight LED flashes | Gas heating lockout. | Gas valve stuck closed on control. |
| Nine LED flashes | Medium pressure switch, high-pressure switch, or PSR relay didn’t close or was reopened. | Refer to status code #3. |
| Ten LED flashes | Polarity. | Correct line voltage polarity. |
| Status codes 1 + 2 | Blower on after power up. | Normal operation. |
| Status codes 1 + 5 | Blower motor lockout. | Control will auto-reset after 3 hours. Refer to status code #4 + 1. |
| Status codes 3 + 5 | Gas valve fault. | RED, YELLOW, or ORANGE wire at the gas valve. |
| Status codes 4 + 1 | Blower motor fault. | Blower failed to reach 250 RPM, or the blower failed to communicate within the prescribed time limits. |
| Status codes 4 + 2 | Inducer motor fault. | Proper vent sizing; restricted vent; failed inducer motor; improper motor wiring; a blockage in the tubing to the pressure switch assembly. |
| Status codes 4 + 3 | The low or medium pressure switch is open while the medium or high-pressure switch is closed. | Low inlet gas pressure; clogged condensate drain; improper pressure switch wiring; water in vent piping; low or medium pressure switch stuck open; disconnected or obstructed pressure tubing. |
| Status codes 6 + 1 | Ignition lockout. | Control will auto-reset after 3 hours. Refer to status code #6. |
