What problems does HVAC equipment in the attic cause, and which ones look like roof leaks?
Short answer. Air handlers and ducts in Georgia attics commonly cause condensate pan overflows, sweating ducts that drip on the ceiling, leaky ducts that waste cooled air, and heat soak that strains the system. Several of these leave ceiling stains that look exactly like roof leaks, so the timing of the stain, after rain or after hot humid days, is the first clue.
Problems that mimic roof leaks
- Condensate overflow: the air handler makes gallons of water on a humid day. A clogged drain line fills the secondary pan, and a pan without a working float switch overflows onto the ceiling.
- Sweating ducts: uninsulated or torn duct insulation in a hot, humid attic collects condensation that drips onto the drywall, often in spots under supply boots.
- Sweating supply registers: cold air meeting humid attic air around poorly sealed boots.
Rule of thumb: stains that grow after storms point to the roof. Stains that grow on hot, muggy days with the air conditioner running hard point to the HVAC.
Other attic HVAC problems
- Duct leaks: supply leaks dump cooled air into the attic; return leaks pull hot attic air into the system.
- Heat gain: ducts sitting in a very hot attic lose cooling before the air reaches the rooms.
- Gas furnace flues: metal flue pipes through the roof need proper flashing, a storm collar and clearances. Rust or a loose collar can leak at the roof.
- Blocked intake: equipment platforms and duct runs packed near the eaves can block soffit vents.
What helps
- Have the condensate line cleared and the float switch tested yearly.
- Seal and insulate ducts.
- Keep balanced attic ventilation, which reduces attic heat and humidity around the equipment.