Run capacitor
Common no-start and weak-compressor failure point. Match the microfarad and voltage rating.
Lennox Error Code 414 Rollout — What It Means
Lennox fault code 414 has two distinct triggers on SureLight control boards: one for gas valve circuit faults (covered in a separate guide) and one specifically for the rollout limit switch circuit. When 414 is paired with a rollout switch trip, the board detected that one or more rollout switches opened during or between heating cycles. Lennox units often have two rollout switches — one per burner bank — and the 414 rollout variant may indicate a single switch tripped or that both switches are in the circuit and one has failed open. This is a safety shutdown condition.
Common Causes
- Blocked flue causing rollout — The most critical cause: combustion gases cannot exit the heat exchanger normally and escape out the front of the burner box, contacting the rollout switch. Any flue restriction can cause this.
- Failed induced draft motor not creating draft — Without adequate negative draft pressure, combustion gases recirculate inside the furnace cabinet and cause rollout even with an open flue.
- Single rollout switch failed open (not a rollout event) — The switch itself fails open without an actual flame rollout. Use a multimeter to test continuity across each switch individually. A switch that reads open at room temperature has failed.
- High gas manifold pressure — Excessive gas pressure creates an oversized flame that can exceed heat exchanger capacity and contact the rollout switches located on the burner deck.
Step-by-Step Fix
- Identify which rollout switch tripped — Lennox furnaces typically have two rollout switches on the burner compartment. Test each one individually with a multimeter: continuity = closed (OK), open circuit = tripped or failed.
- Reset manual-reset rollout switches — Press the reset button firmly on each tripped switch. If a switch will not reset after cooling, it has failed and must be replaced.
- Confirm no actual rollout conditions exist — Inspect the flue path and inducer before resetting. Resetting without clearing the root cause will result in immediate re-trip and potential heat exchanger damage.
- Check manifold gas pressure — Connect a manometer to the gas valve test port. Natural gas should read 3.2–3.7” W.C. at the manifold. High pressure (>3.8” W.C.) requires gas valve adjustment or replacement.
- Test inducer and pressure switch — Verify the inducer runs to full speed and the pressure switch closes before allowing the ignition sequence to proceed on the next test cycle.
Parts Often Needed
| Part | Notes |
|---|---|
| Rollout limit switch (manual reset) | Buy matching pair if replacing one; Lennox uses 190°F or 250°F rated switches depending on position |
| Induced draft motor | Replace if insufficient draft is confirmed cause of rollout |
| Gas valve | Replace only if manifold pressure is non-adjustable and out of spec |
Technician Tips
Lennox furnace error codes are displayed as a series of LED flashes on the SureLight or integrated control board. A slow flash usually indicates normal operation, while rapid flashing points to a specific fault code. Code 1 = no previous code (normal standby). Code 2 = pressure switch failed open — check the vent, condensate drain, and inducer motor. Code 3 = pressure switch failed closed — replace the switch. Code 4 = high temperature limit — check airflow. Lennox systems with the SureLight igniter are particularly sensitive to gas pressure — verify 3.5” WC on natural gas before troubleshooting further. A 5-minute gas pressure check can save an hour of unnecessary component swapping.
Need Replacement Parts?
Before ordering, match the furnace part to the model number, electrical rating, and failure symptom. Check current prices on Amazon - prices and availability change frequently.
When to Call a Pro
Rollout events are a carbon monoxide and fire risk. If the switch tripped due to an actual flame rollout rather than a component failure, do not operate the furnace until a technician identifies and corrects the draft or combustion issue. A cracked heat exchanger can produce rollout conditions and is not field-repairable.