Skip to main content
Interior

Test Bathroom Exhaust Fans

EASY10 minInteriorPart of Spring Maintenance

Why It Matters

A non-functioning exhaust fan traps moisture in your bathroom, leading to mold growth on walls, ceiling, and in hidden spaces.

Quick Guide

  1. 1

    Gather your tools and materials

    You'll need: basic tools. Materials required: necessary materials.

  2. 2

    Perform the test bathroom exhaust fans

    Turn on each bathroom fan and hold a tissue to the grille to verify it draws air. Clean the fan cover.

  3. 3

    Verify and clean up

    Check that the work was completed correctly and clean up your workspace. If if fan does not draw air or makes loud grinding noises, consider calling a professional.

Get the full guide personalized to your home

Sign up free to see the full guide for YOUR home — tailored to your climate zone, systems, and property.

Sign up free

Community Tips

TipKasa Team

Turn on the exhaust fan and hold a tissue or light paper towel near the grille—if it's drawn toward the vent with steady suction, the fan is functioning properly, but weak or no suction indicates blockage or motor failure requiring cleaning or replacement. Panasonic WhisperCeiling ($150-250) models include replaceable filters that should be checked quarterly to maintain optimal airflow and prevent moisture damage.

WarningKasa Team

Never ignore a bathroom exhaust fan that's running but producing little airflow, as trapped humidity accelerates mold growth behind walls and can cost $2,000+ to remediate once structural damage occurs. Most failures stem from ductwork disconnection or crushed flexible ducting in attics, not the fan unit itself.

Tool RecKasa Team

A duct borescope camera like the Ryobi ONE+ 18V ($70-110) allows you to inspect ductwork from inside the attic without dismantling connections, revealing lint accumulation, bird nests, or damage that visual inspection from the grille alone cannot detect. ---