Corroded Hinge Kit
What it is: The metal brackets connecting the fan to the roof are rusting or seized.
Why it happens: Grease and moisture sit in the hinges, causing corrosion.
Our recommendation: Replace the hinge kit (usually $400–$800). If it's bad enough,
it affects roof integrity.
Worn or Sticking Damper
What it is: The flapper that closes off the roof opening when the fan isn't running is stuck.
Why it happens: Grease buildup, broken hinges, or age.
Our recommendation: Clean or replace (usually $200–$500). A stuck damper costs you in energy loss.
Bearing Wear (Fan Grinding/Noise)
What it is: The fan shaft bearing is worn, causing noise and resistance.
Why it happens: Age, heavy use, and lack of bearing maintenance.
Our recommendation: Early: lubrication (low cost). Late: bearing replacement ($600–$1,500 total).
Roof Structural Damage
What it is: Grease overflow has corroded or damaged the roof membrane or structure.
Why it happens: Long-term grease neglect. Acid in grease eats roofing materials.
Our recommendation: Document with photos. Refer to roofing contractor. Could be $1,000–$5,000+.
Ductwork Dents or Leaks
What it is: The metal ducts are dented, rusted, or have gaps causing grease leaks.
Why it happens: Impact damage, age, or improper maintenance.
Our recommendation: Small dents: leave as-is. Leaks: patch (low cost) or section replacement ($300–$1,000).
Blower Motor Issues
What it is: The fan motor is struggling, overheating, or making electrical noise.
Why it happens: Age, electrical load from grease-choked system, or bearing pressure.
Our recommendation: Not our wheelhouse — we refer to an HVAC specialist. Usually $500–$2,000 to replace.