HVACopediaTrane · Furnace
E6.3 Igniter open or igniter relay fault
What the control is telling you
Either the igniter circuit is open/shorted or the IFC igniter relay has failed (stuck or not switching).
Applies to: Trane S8V2 (80%, 2-stage, variable speed, Link) and S8B1 / S8X1 / S8X2 (80%, 1- and 2-stage)
Likely causes
- Broken igniter
- Damaged igniter harness or loose plug
- Failed igniter relay on IFC
Test and repair steps
- Warning: Turn off power before unplugging connectors or measuring resistance.
- Call for 1st stage heat and watch for igniter glow.
- No glow measure 120 VAC between IGN-H and IGN-N on the IFC during warm-up; no voltage means replace the IFC.
- Voltage present but no glow check the harness and connectors, then unplug the igniter and read resistance - about 37 to 70 ohms at around 75 F is good; outside that, replace the igniter.
- If the igniter stays on when it should not, the relay is stuck - replace the IFC.
Settings for these units
Clearance to combustibles · Trane S8V2
| Cabinet width | Vertical sides / top | Horizontal sides / top |
|---|---|---|
| 14.5 in. | 0 / 1 in. | 1 / 2 in. |
| 17.5 in. | 0 / 1 in. | 1 / 2 in. |
| 21.0 in. | 0 / 1 in. | 1 / 3 in. |
| 24.5 in. | 0 / 1 in. | 1 / 5 in. |
24 in. front service access.
3 in. in front of the combustion air openings.
Return filter size by cabinet width · Trane S8V2
| Cabinet width | Filter |
|---|---|
| 14-1/2 in. | 1 - 14 x 25 x 1 in. |
| 17-1/2 in. | 1 - 16 x 25 x 1 in. |
| 21 in. | 1 - 20 x 25 x 1 in. |
| 24-1/2 in. | 1 - 24 x 25 x 1 in. |
Filters are field supplied and mounted outside the cabinet.
Over 1600 CFM upflow: return on both sides, one side plus bottom, or bottom only.
- Return filter size by cabinet width · Trane S8B1, Trane S8X1, Trane S8X2
Models that show this code
37 models in Trane S8V2, Trane S8B1, Trane S8X1, Trane S8X2
Other codes on the same units
- E4.2 Flame rollout switch open
- E05 Flame sensed when no flame should be present
- E6.1 120 V polarity reversed
- E6.2 Ground not detected
- E7.1 1st stage gas valve (MVL) powered with no call
- E7.2 Redundant relay (HLO output) on with no call
- E08 Low flame signal (still running)
- E11 Gas valve relay / valve circuit fault
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Source: Trane FNR-SVX003A-EN (S8V2 installer's guide) - section Integrated Furnace Control Display Codes, Table 37 Error codes; Trane FNR-SVX003A-EN (S8V2 installer's guide) - section Troubleshooting (flowcharts); Trane 18-CE14D1-1A-EN (S8B1/S8X1/S8X2 installer's guide) - section Integrated Furnace Control Display Codes, Error Codes. Summarized in our own words; check the original manual for your model.
Homeowner looking at this code? See what it means for you and when to call a technician.
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.