Trane SWT1277 Limit Switch a blocked secondary heat exchanger

a blocked secondary heat exchanger

Direct Replacement Logic: Effectively replaces the discontinued DMPR-RS201 without requiring hardware modifications

While the 125401 sensor lead is used across several series

Constructed from a heat-resistant manifold compound

or a failing blower motor rather than a faulty switch

Trane SWT1277 Limit Switch a blocked secondary heat exchangerThe Trane SWT1277 Limit Switch is a critical safety component designed for precise thermal regulation in Trane and American Standard HVAC furnaces. As a high limit automatic reset switch, it monitors the supply air and heat exchanger temperatures to prevent hazardous overheating. This genuine OEM furnace limit switch features a 3 inch insertion length, ensuring accurate sensing deep within the plenum or blower housing. Operating on a normally closed