What does an excessive draft drop through the heat exchanger indicate?

An excessive draft drop through the heat exchanger indicates heavy soot and scale deposits within the system. This phenomenon occurs when there is an accumulation of combustion byproducts, such as soot, which diminishes airflow and can obstruct the heat transfer process within the exchanger. As these deposits build up, they create a resistance to the flow of flue gases, leading to a higher draft drop than expected. This condition not only hampers the efficiency of combustion by limiting oxygen supply but can also risk safety by potentially causing incomplete combustion and increasing the chances of dangerous byproducts, such as carbon monoxide, being released into the living space.

Monitoring draft levels is crucial for maintaining proper system performance, as it provides insight into the condition of the heat exchanger and highlights the need for maintenance or cleaning to prevent further efficiency losses and enhance safe operation.