Where is a stack relay typically found?

A stack relay is typically found mounted in the flue pipe due to its specific function in monitoring the exhaust gases produced by the heating system. Its primary role is to detect whether there is proper draft or airflow within the flue, which is essential for the safe and efficient operation of combustion appliances. If the stack relay senses that the draft is insufficient, it can interrupt the ignition process, thereby helping to prevent the release of harmful gases into the living space.

Positioning the stack relay in the flue pipe allows it to effectively respond to changes in the exhaust flow, ensuring that the heating system can operate safely. This strategic location plays a crucial role in providing a safety interlock that safeguards against potential hazards, such as backdrafts or combustion appliance malfunction.