Why Condensate Drains Clog And How to Stop It

It all starts with humidity, stagnant water, and the switch from copper to aluminum coils, which has opened the door to more microbial growth and more drain issues than ever before. From there, the conversation moves into practical solutions technicians can try in the field, whether it’s a small piece of brazing rod dropped into the line, a copper-impregnated drain line, or building an overflow valve box for units with nowhere else for water to go.

Topics covered:

• Why stagnant water and climate drive clog frequency
• How aluminum coils changed microbial growth compared to copper
• Using silver and brazing rod to help reduce buildup
• Why bleach should be avoided in condensate lines
• The value of hot water and shop vac flushing technique
• How unit slope and support issues contribute to drainage problems
• A rare real-world case: an unusual clog caused by slugs
• Alternative drain routing and valve box overflow solutions