Reznor 113216 Blocked Vent Switch

The Reznor 113216 Blocked Vent Limit Switch is a safety control for gas-fired heating systems that monitors venting conditions. It is placed in unit heaters and similar equipment where proper exhaust flow is required during combustion. The switch detects restricted or blocked venting and opens the control circuit if unsafe draft conditions occur, stopping burner operation to protect the heat exchanger and combustion chamber in HVAC systems. It is mounted near the draft hood area and is used in manual-reset safety circuits. This component is replaced during servicing when vent safety controls fail or when restoration of proper airflow protection is needed.