How AC Condensate Drain Lines Get Clogged With Slime

Why is my AC leaking water inside the house? Often it’s not a broken unit — it’s HVAC condensate with nowhere to go. This documentary traces the full condensate path: evaporator coil → primary drain pan → trap → drain line → secondary pan and float switch. You’ll see how a small biofilm clog turns normal dehumidification into a ceiling leak and water damage. What you’ll learn: • How air conditioners make gallons of condensate every day • Why drain traps and slope matter • How AC drain line clogs form (slime / biofilm) • Secondary pans, float switches, and code-required backups • Safe things to check before calling a pro ⏱ TIMESTAMPS 0:00 Water from the ceiling: the summer alarm 0:24 How evaporator coils generate condensate 0:51 The primary drain pan and outlet pipe 1:36 Why drain lines need traps 2:20 Where condensate goes after the trap 2:53 When blockages begin: biofilm and slime 3:51 Secondary drain pans and visible termination 4:45 Float switches: the third layer of protection 5:19 Common failure modes and maintenance gaps 6:57 What you can observe safely 8:08 Maintenance chemicals vs. mechanical cleaning 8:40 Climate, codes, and condensate risk 9:34 The lesson: water needs a clear path General educational information — not an inspection, diagnosis, or substitute for qualified local professionals and current codes. Subscribe to Home Systems Lab for evidence-led documentaries on residential building science and home mechanical systems.    / @homesystemslab   #HVAC #ACWaterLeak #CondensateDrain #BuildingScience #HomeMaintenance