Trane 6 Flashes Error Code — What It Means
Six LED flashes on a Trane furnace control board indicates the rollout switch has tripped. The rollout switch is a thermal safety device mounted on or near the burner assembly. It opens if flame rolls out of the heat exchanger — typically caused by a blocked flue, a cracked heat exchanger, a restricted combustion air path, or an induced draft motor that can’t maintain proper draft. A tripped rollout switch is a serious safety event and should not be ignored or bypassed.
Common Causes
- Blocked or restricted flue — Bird nests, ice dams, collapsed vent pipe, or debris in the flue pipe create back pressure that pushes flame out of the heat exchanger opening, tripping the rollout switch.
- Failed or weak induced draft motor — If the inducer can’t pull adequate combustion gases through the heat exchanger, pressure reverses and combustion gases roll out toward the rollout switch.
- Cracked heat exchanger — A crack in the heat exchanger disrupts normal flame containment and can cause rollout conditions. This is a critical safety issue requiring immediate furnace shutdown.
- Oversized burner flame or bad gas valve — A gas valve passing too much gas produces an oversized flame that overruns the heat exchanger opening and contacts the rollout switch.
Step-by-Step Fix {#fix}
- Do not bypass the rollout switch — The rollout switch is a one-time (or auto-reset) safety device. Bridging it eliminates a critical carbon monoxide and fire protection. Treat the trip as a real event and find the cause.
- Inspect and clear the flue path — Disconnect the flue pipe at the furnace and inspect for blockages from the furnace to the termination point. Clear any debris, ice, or nesting material.
- Check the induced draft inducer — Start the furnace and verify the inducer spins up quickly and runs at full speed. A laboring or slow inducer will fail to maintain draft. Check amp draw against nameplate.
- Reset the rollout switch — If the switch is a manual-reset type, locate it on the burner box (typically a red or white button). Allow the switch to cool completely, then press the reset button firmly.
- Inspect heat exchanger visually — With the burner off and panels removed, use a flashlight and mirror to inspect the heat exchanger for cracks, holes, or deformation. If cracks are found, shut the furnace down.
Parts Often Needed
| Part | Notes |
|---|---|
| Rollout switch (manual reset) | Amazon | Match the correct temperature rating for your model |
| Induced draft motor | Amazon | Replace if running slow, noisy, or failing to start |
| Flue vent pipe section | Amazon | Replace collapsed or damaged vent segments |
When to Call a Pro
A tripped rollout switch that cannot be attributed to a blocked flue is a strong indicator of a cracked heat exchanger — a condition that poses carbon monoxide risk. Do not operate the furnace until a licensed technician performs a full heat exchanger inspection.