What are the three reasons why a pump will fail to function?

Residential HVAC condensate pumps typically fail to function due to three primary mechanical, electrical, and maintenance-related reasons. First, electrical failure occurs when a power surge fries the motor windings, a circuit breaker trips, or the unit loses wall outlet power, rendering the motor completely dead. Second, mechanical failure happens when the internal float switch mechanism becomes permanently jammed or stuck in the "up" position due to thick algae slime and mineral scale buildup, or when motor bearings seize up. Third, plumbing or drainage failure occurs when the discharge tubing or check valve becomes completely clogged with dust sludge and debris, preventing water from escaping even when the motor runs. You can troubleshoot these issues with a multimeter and visual checks. You can verify resolution when clearing clogs or replacing dead units restores normal pumping.