Reznor 121275 Block Installing this in a natural

Installing this in a natural gas system will result in improper combustion and potential safety hazards

While it is often found in systems with similar nominal voltages

Built with a dry case and a black steel housing

Using a tube that is too short will result in inadequate air sampling and potential code violations

Reznor 121275 Block Installing this in a naturalThe Reznor 121275 Stack Flue Block is a high limit safety component engineered specifically as an Energy Cutout Device (ECO) for commercial and industrial gas fired heating units. Designed to monitor the integrity of the ventilation system, this blocked vent switch acts as a critical failsafe by measuring exhaust temperatures at the flue. If the sensor detects a restriction, backflow, or overheating condition where temperatures reach the 275F trip