Trane

S8X1

Furnace · S-series · single-stage · 80% · Cat I

Trane/AS S-series 80% single-stage. Split out of the S8X2 plate so a single-stage cabinet does not inherit two-stage W2 / high-draft checks. Category I metal vent. Same-looking E-decimals as S9 if the IFC family matches — physics are chimney, not collector.