The exhaust fan in the bathroom stopped working: what to check in winter

But the cause might not be an obstructed duct at all. In winter, windows are often closed, and sometimes there’s simply no way for air to enter the apartment. Therefore, it’s better to start with a few simple checks rather than buying a new fan.

Take a thin piece of paper or a tissue and hold it near the ventilation grille.

When the natural exhaust is working, the paper may drift away from the opening or be drawn toward it. If the sheet remains still, it means the airflow is weak or absent. However, there’s a nuance: the wick does not indicate how much air the ventilation system is removing. Even if it’s placed on the grille, this doesn’t prove that enough moist air is being expelled.

If the paper isn’t being drawn in, don’t rush to conclude that there’s a blockage. Factors such as temperature, wind, pressure differences, and air inflow affect the exhaust flow.

Also, do not check the ventilation system using a lighter or candle. An open flame isn’t necessary for such testing.

In a regular apartment with natural ventilation, air must enter from somewhere, flow through the rooms, and exit through ventilation ducts. In winter, tightly closed windows can interfere with this process.

Perform a simple test:

1. Place a tissue near the vent with the windows and bathroom door closed.

2. Slightly open the bathroom door and repeat the test.

3. Then slightly open a window in the living room and check the tissue again.

If the airflow increases when the door is open, it may be that the bathroom door is too tight, preventing air from passing through. If a noticeable difference appears after opening the window, it’s worth checking how air flows into the apartment.

But these are just hints. Even if a pull is felt, the condition of the ventilation duct remains unverified.

Sometimes the problem is visible without any tests.

Dust and lint accumulate on the ventilation grille, which can gradually block some of the openings over time. The removable grille can be cleaned according to the instructions without damaging its attachments.

If an electric fan is installed behind it, the power must be turned off before maintenance, and the manufacturer’s instructions must be followed. It is not advisable to disassemble an unfamiliar device on your own.

Now look at the bathroom door. To allow proper air circulation between rooms, a gap under the door leaf or special ventilation inserts are usually provided. After repairs, this passage is sometimes blocked by a high threshold or a door that is too tight. If airflow is significantly better with the door open, discuss with the contractor an appropriate method to ensure air circulation. There’s no need to cut the door leaf randomly.

You should never cover the ventilation grille, even if cold air sometimes gets through it.

Suppose the grille is clean, the door is open, and the window is slightly ajar, but the towel still doesn’t react. Or the air is clearly flowing back into the bathroom from the ventilation opening.

This is a reason to contact the management company and ask them to check the ventilation system.

The cause could be the condition of the common ducts, impaired air circulation, or pressure differences. It’s impossible to determine the cause on your own using the towel. If similar problems exist among neighbors in the same building, mention this in your request. But even if only you are experiencing the issue, a check is still necessary. It’s better to leave a written complaint describing the problem: when the moisture appeared, how the exhaust fan is performing, and whether there is backdraft.

The specialist should check the system and measure air flow if necessary. There is no need to enter the ductwork with a rope or vacuum cleaner.

Particular attention should be paid to ventilation issues in apartments with gas appliances, as proper air exchange is crucial for safety there.

It seems sufficient to install a powerful fan instead of a regular grille. But if there’s no source of air supply, even a good device won’t ensure proper air circulation. Additionally, in an apartment building, the ventilation duct may be part of a shared system. Connecting an additional fan could disrupt its operation, so the feasibility of such installation needs to be checked in advance.

If a fan is already installed and making noise, that also doesn’t guarantee proper exhaust function. It may be rotating, but removing too little air.

A faulty device should be inspected by a professional, while installing and wiring a new one in the bathroom must comply with electrical safety requirements.

While the ventilation is being checked, it’s important not to introduce extra moisture into the room.

After taking a shower, wipe away water from glass partitions and walls, pull back curtains, and avoid stacking wet towels. It’s better to dry clothes outside the bathroom where air circulation is poor.

If there is a working exhaust fan, use it during showers and for some time after, following the instructions.

Dark spots in corners shouldn’t be simply painted over. The cause of humidity must be addressed first, otherwise mold may reappear.

The most important thing is to check the entire air path. First, the grille, then the bathroom door, and the airflow from the rooms. If home checks don’t reveal the cause or if backdraft is detected, ventilation diagnosis is needed, rather than simply installing a more powerful fan arbitrarily.