How often should attic fans be replaced?
Short answer. Attic fans are replaced when they fail or get damaged, not on a fixed schedule, and many last around a decade or more in a Georgia attic. The key replacement moments are a dead or noisy motor, a cracked dome after hail, a rusted or leaking base, and every roof replacement, when you should decide whether to keep the fan at all.
Triggers that mean replace
- Motor failure: it hums but will not spin, trips the breaker, or grinds. Sometimes a motor swap is enough.
- Hail damage: cracked plastic domes or dented metal domes. A crack is a leak waiting for the next storm.
- Rust at the base: rust through the flashing flange leads to leaks around the fan.
- Control failure: a stuck thermostat or humidistat can often be replaced on its own.
- Solar fans: weaker output on sunny days as the panel ages.
A five minute yearly check
- On a warm spring day, turn the thermostat down until the fan starts.
- Listen for grinding or squealing.
- Look at the dome from the ground with binoculars for cracks or missing screen.
- In the attic, look for water stains around the fan opening.
- Reset the thermostat to its normal setting.
At every roof replacement
The fan's flashing ages with the roof, so it should never just be reused under new shingles. You have three choices: install a new fan with fresh flashing, reuse a fan in good shape with new flashing where possible, or remove it, deck over the opening and switch to ridge venting with soffit intake. Many Georgia homes are better off with the last option, since a fan alongside a ridge vent can pull air in through the ridge. See ridge vent vs box vents and roof replacement day.