Water In Floor Air Vents -Causes & Water Removal

Wondering why is there Water in your floor air or heating vents? Not sure how to remove the water & fix any water damage?

In this guide you will learn:

  • Why is there water in your floor vents,
  • What happens if water gets in your floor vents,
  • How to remove the Water
  • How to Prevent Water getting into your floor air heating vents.

Why Is There Water In My Floor Vents?

1.Leaks and spills

A common cause of water in your vents can be a leak or large spill, for example, from a burst pipe.

Often times a washing machine or dishwasher can overflow and leak water into your floor vents as well.

2. Poor insulation or insufficient sealing of the ducts

This causes a temperature difference or change in airflow which creates excess condensation which can easily clog the condensation drain or freeze the evaporator coil.

3.Clogged condensate drain

This may also be why water is in your vent as the condensation cannot drain.

A dirty air filter may be the cause of excess condensation as a dirty filter will restrict the airflow creating a temperature difference that creates condensation. If it’s dirty, it’s time to replace it.

This causes the evaporator coil to freeze and form frost as the air gets trapped in the dirty air filter and as it melts water is released into the system.

If it is frozen it may be wise to contact a professional who can get rid of the frost and all moisture.

4. Flooding

Flooding can also cause water to get in your floors vents and is sometimes left behind in vents after standing water is removed.

Standing water in vents is more difficult to manage.

You might have to invest in a wet vac or get in touch with professionals who have this equipment.

Also, if there is water in your floor vents after heavy rain it may be because of a broken sump pump that will need fixing or replacing or the water may be making its way through cracks in your roof or slab foundation.

Causes Of Water In Floor Vents In Slab Foundation

Groundwater seepage through cracks is very common ,as when it rains, water can infiltrate the ground and make its way into the basement through hairline cracks in slab foundations or walls.

It is mostly caused by improper grading, downspouts or guttering as it means water cannot escape so it will build up and seep into the ground finding its way into the foundation.

Cracks in the foundation can be caused by water expanding the soil creating pressure and making the cracks. This means now the water can easily pass through into your house and then into floor vents.

As floor vents are the lowest point of your basement water is most likely to build up here.

Water in Floor Vents?

Call 844-994-1288 for a Risk Free estimate from a Licensed Water Damage Restoration Specialist in your area.

We Can Help Remove the Water from your Floor Vents & Repair any Water Damage.

What Happens If Water Gets In Your Air Vents?

Even though a small amount may seem harmless, any moisture can cause issues like mold or further damage to your vents or property and should not be ignored.

If it is only a small amount of water like from condensation or a small spill, you can usually clean it out yourself using some basic equipment.

If you have had a recent flood or large leak and there is standing water it is best to contact a professional team who has the equipment to remove water effectively.

How To Get Water Out Of Floor Vent

1. Assess the situation.

First, take a look at your situation and think of if the water was caused by a one-time occurrence like accidentally leaving a window open during heavy rain, or is it ongoing like a ruptured pipe.

If it is ongoing you must stop the issue first to make sure no more water gets in the floor vents. The first step in stopping a leak will be by turning off your homes water supply.

Think about the source of the water, is it clean like rain/tapwater or is it dirty water.

If the water is in between such as coming from a burst sink drain then wearing some equipment such as gloves and goggles are recommended. Also, you should wear appropriate clothing such as long-sleeved shirts or pants.

Make sure any water outside of the vent is removed first before moving onto removing water from your floor vents.

If the water is live sewage it is heavily advised you call water damage experts as there is most likely dangerous bacteria in the water posing health risk.

This might mean the vent ducts will have to be removed or replaced for the safety of you and others.

Consider how long the water has been in the vent. Taking action as quick a possible is crucial as mildew growth and rusting can happen within a day.


  • Dry rags or towels.
  • A long handed dustmop – optional.
  • A bucket.
  • A torch or headlight.
  • A wet/dry vac with any nozzles or filters you may want – this is only needed for standing water.
  • A fan or dehumidifier.
  • Materials like caulk or insulation for filling in cracks or insulating around the vents. You can get these at your nearest DIY store or online.
  • Anti-bacterial spray for cleaning.

3. Preparations

Clear the area around the vent so moisture doesn’t spread to any furniture, this also helps making the vent easier to get to.

– Turn your HVAC off at the switch but if you cannot find the switch go to your fusebox and turn it off from there.

-Remove the vent cover/opening.

-Get your equipment at hand and examine how much water there is.

-If there is standing water in your floor vents please get your wet/dry vac ready or call a professional team who has this equipment.

-If you cannot reach all parts of the vent then either use a long mop or lift up your flooring and unscrew the ducts to reach the vent.

4. Getting to work

From here onwards it is fairly straightforward but can take some time depending on if you have to lift carpet and remove floorboards to reach harder to get vents.

Be careful when removing the water and try not to loosen any screws or vents which could spread the water into the insulation around the vent.

For standing water get your shop vac and remove as much water as your can.

Then use your towels or mop and pad the water so it gets absorbed and then ring it out into your bucket and repeat until almost all moisture is gone.

You can also use a antibacterial spray to clean the vents or get a professional to clean it for you.

5. After removal

Once most water is removed from your floor air or heating vents consider pointing a fan or dehumidifier at the vent so it can help dry out any left over moisture. For a large floor vent system you might need multiple.

After all moisture is removed please inspect the vents for any improper sealing or cracks and fill them in using caulk which you can find at your local DIY store.

Check the insulation around your vent and if it is wet it will need removing and replacing.

If there is not any insulation make sure the area is dry and then apply insulation – you can buy this at your nearby DIY or hardware store.

After the floor vents are dried put any floorboards and flooring back and put your vent covers back.

Fix any issues causing condensation like a dirty air filter.

Mold Issues

Any moisture left in air vents can cause mold to grow which harvests bacteria that can be harmful to your health.

You need to act fast as the mold or mildew can develop within 24-48 hours. It is sped up if they are heating vents as mildew thrives in warm and humid conditions.

Mold can also be costly as if mold is allowed to grow and you still operate your ventilation unit the spores can be spread to walls, furniture or carpet.

How To Prevent Water From Getting In Your Floor Vents

Here’s a couple of ways to prevent water from getting into your air vents in future.

For leaks, you should find the issue, for example for a burst pipe repair it either by replacing or fixing the pipe.

You should also fix your roof or any cracks where water can enter after the rain by replacing the broken material or by using a filler.

If it is an appliance like a washing machine leak you should get it repaired or replaced as well.

It is best to ensure your vent system is regularly being cleaned and maintained so the airflow can circulate correctly stopping potential condensation or water entry points.

When To Call A Professional

Removing moisture from your floor vents does come with some risks to yourself or your home. If you are concerned for your safety it is best to get professional help.

If mold has grown in your vents please contact professionals as it can cause serious respiratory issues or bacterial infections.

The mold can also spread to carpet, walls or furniture if the vent is still used after mold had grown so please stop using the unit once you notice mold has grown.

Water damage can cause costly and irreversible effects to your house depending on how far it is allowed to persist.


We have Water Damage Restoration Technicians that can help Find the Source of the Water in your Air Vents & Remove it.

For Disasters of all Sizes,available in 95% of the USA

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