Air Systems Cleaning Specialist (ASCS) Practice Exam – Prep & Study Guide

The presence of water on the floor after cleaning the ductwork of a residential high-efficiency gas furnace is most likely attributed to a disconnected condensate pump. High-efficiency gas furnaces produce condensation as a byproduct of the combustion process, and this condensation is typically collected and pumped away from the unit by the condensate pump. If this pump is disconnected, the accumulated water has no proper outlet, leading to water pooling on the floor nearby.

In the context of this scenario, while a disconnected gas line or leaking refrigerant liquid line can lead to various issues, they would not directly result in water accumulation in the way a problem with the condensate pump would. Similarly, a leaking condenser coil is associated more with cooling systems and would not pertain to a gas furnace. Therefore, the disconnect in the condensate pump provides the most plausible explanation for water leakage in this situation.