# e4.1 · Trane · S8V2 — Residential gas furnace fault code lookup by brand

For e4.1 · Trane · S8V2, brand is Trane; model / control board is S8V2; fault code is e4.1; fault name is Open reverse air-flow limit switch, verified against its source on 2026-08-28.

- **Brand:** Trane
- **Model / control board:** S8V2
- **Fault code:** e4.1 _(verified: appears in the quote below)_
- **Fault name:** Open reverse air-flow limit switch _(verified: appears in the quote below)_

## What the source says

> e4.1 Open reverse air-flow limit switch

## Source

- https://elibrary.tranetechnologies.com/public/residential-hvac/Literature/Installation%20Operation%20and%20Maintenance/FNR-SVX003A-EN_10312025.pdf

Last verified: 2026-08-28. Review by: 2028-08-27.
Part of [Residential gas furnace fault code lookup by brand](https://referencesource.org/residential-furnace-fault-codes-by-brand/).