The core idea
Cooling and high-efficiency equipment create water that must drain continuously without blockage, freezing or overflow.
How the mechanism works
Condensation collects on cold coils or flues and is routed through traps, pans and drain lines.
When it becomes relevant
Typical trigger: Cooling operation, humid weather or heating-condensate cycles.
Evidence that supports this interpretation
- Water appears only during equipment operation
- A pan contains water or deposits
- Drain lines show restriction or poor slope
Evidence that weakens it
- The equipment is off
- Rain enters the same area
- A pressurized pipe is leaking
What this concept cannot prove alone
A single observation, image or meter reading cannot confirm the complete failure pathway. Use this concept to form better questions, compare alternatives and decide which safe observation would be most informative next.
Safety and professional boundary
Service inside HVAC or combustion equipment should be performed by qualified technicians.
Primary references for this topic family
These references ground the general building-science or safety context. They do not diagnose a specific house, replace local requirements or certify a repair.
