What is the primary function of a blower delay relay in a gas furnace?

The primary function of a blower delay relay in a gas furnace is to ensure that the blower continues to run after the burner has shut off. This is crucial for effectively distributing residual heat from the heat exchanger throughout the living space, thus maximizing comfort and efficiency. The continued operation of the blower helps to prevent overheating and allows the remaining warm air to be circulated rather than trapped in the furnace, which could lead to wastage of energy.

Furthermore, by delaying the shutoff of the blower, the system can also help prevent issues such as condensation on the heat exchanger, which can lead to corrosion or other long-term damage. The blower delay relay acts as an important component in maintaining proper airflow and performance of the furnace, aiding not only in comfort but also in the longevity of the heating system.