Water dripping from a bathroom extractor fan can come from condensation inside a cold duct, rain entering through the outdoor vent, or a leak above the ceiling. The timing is your first clue. If water is coming through the fan housing, stop using the fan and arrange an inspection by a qualified electrician. Leave the cover in place.

Is it condensation, rain or a leak?

  • After a hot shower, especially in cold weather. Warm, moist air may be condensing inside a duct that runs through an unheated loft.
  • During wind-driven rain, even when nobody has showered. An installer can check whether rain is entering at the outdoor terminal or whether water is coming from elsewhere above the ceiling.
  • In dry weather or with staining away from the fan. A plumbing leak or water already trapped above the ceiling may be involved. Note where the damp patch starts and whether it spreads.

Why does a cold loft duct make a fan drip?

Moist bathroom air cools as it travels through an unheated space. Water can form on the inside of the duct, collect in a sag, and drain back toward a ceiling grille. Ask the installer to check duct support, insulation and the route to the outdoor terminal. The right way to manage condensation depends on the route and the fan manufacturer's instructions.

Read the bathroom fan ducting and placement guide.

What can you check before calling an installer?

Record when the drip starts, how long it lasts and whether it follows showering or rainfall. Note whether the fan is on a wall or ceiling. Photograph staining from floor level, and look for obvious damage to the outdoor grille if it is visible from ground level. Pass these observations to the installer.

Will a replacement fan stop the dripping?

A replacement may be needed if water has damaged the unit or it is unsuitable for the installation. If the cause is a cold or poorly supported duct, rain ingress or a leak above the ceiling, that cause needs attention. Once the fault is identified, use the duct diameter, required installed airflow and preferred controls to shortlist a replacement.

Read the bathroom extractor fan buying guide or compare bathroom extractor fans.