Does a washing machine need to be vented outside?

Author: Nolan Emmerich  |  Last update: Thursday, December 25, 2025

Every plumbing fixture in your home needs proper ventilation to the outside. Failure to vent your washer means you will have to deal with a surge in indoor humidity. A poorly vented washer releases a tremendous amount of warm, moist air directly into your home.

What happens if the washing machine is not vented?

If there was no vent, the spin cycle would not be able to 'dry' the clothes at all. It also facilitates both the fill and draining process. Air movement has it's place in the overall washing cycle, as well as allowing built up moisture to dissipate somewhat while it is at rest.

What is the best way to vent a washing machine?

The most efficient way to vent your washing machine drainpipe is to run the pipe into your vent stack. The vent stack is the pipe that connects to your plumbing system and exits through the roof. It's set up this way to allow gases to flow out of your home easier.

Can a washing machine be drained outside?

No. You should not drain your washing machine directly into the backyard, as this can cause harm to the environment. The wastewater from the washing machine contains chemicals and detergents that can be toxic to plants, animals, and even humans if exposed to them for a long time.

How much ventilation does a washing machine need?

Tips for sufficient ventilation

Ensure that there is a distance of at least 50mm between the appliance and the wall behind.

Dos & Don’ts of Laundry Plumbing - The Building Expert - 2020

Does a washing machine need to be vented?

Every plumbing fixture in your home needs proper ventilation to the outside. Failure to vent your washer means you will have to deal with a surge in indoor humidity. A poorly vented washer releases a tremendous amount of warm, moist air directly into your home.

Does a washing machine vent need to go through the roof?

The vent stack, or waste stack, is a vertical pipe that connects to your home's plumbing and exits through the roof. Building codes require all homes to have at least one vent stack to allow sewer gasses and built-up air pressure to escape the home.

Where should your washing machine drain into?

In most cases, you have two options for draining water from your washer. Option one is to connect the drain hose to a standpipe, and option two is to place the drain hose in a nearby sink.

Can I put my washing machine outside?

On a porch or veranda

However, if this is your only option, you should always be sure to have all plumbing and electrical work done by professionals as with other types of storage. You may also want to build a sturdy cover for your washing machine to protect it from the elements (and to stop it looking unsightly).

Does a washing machine waste pipe need to be high?

The drain hose should be connected to the standpipe at the correct height for it to work properly. Ensure the highest point of the water drain hose is a minimum of 40cm and a maximum height of 100cm from the floor.

What is the plumbing code for a washing machine drain?

According to the Universal Plumbing Code, the standard drain size for a washing machine is 2 inches. The absolute minimum should be about 1 1/2 inches. However, keep in mind that wash load capacities can vary by up to 400% or more depending on the model.

Why do washer dryers not need a vent?

Ventless dryers, including condenser and heat pump types, don't require an external vent. In a condenser dryer, warm air circulates through the drum and is cooled by a heat exchanger instead of being vented outside. The cooled air turns moisture into water, collected for disposal.

Should you air your washing machine?

Leave the Door Open. After each wash cycle, leave the door of your washing machine slightly ajar to allow air circulation and prevent mold and mildew growth in the drum and seal.

Should you air out washing machine?

DO leave your washing machine door open after use. This will allow it to air out and help prevent mould and mildew from growing – so no more nasty smells lingering in the kitchen.

What happens if a drain is not vented?

When drain lines aren't properly vented, low pressure inside the pipe can suck water out of the traps, letting sewer gas in. Air pressure imbalances inside the drain pipe can restrict water flow and cause sluggish draining, often mimicking a partial clog inside the pipe.

Should a washing machine drain have a trap in it?

The answer to the question, “Does a washing machine drain need a trap?” is a resounding yes. Installing a drain trap is essential for both functionality and safety. It protects against backflow, prevents sewer odors, and helps maintain your plumbing system.

Can I put my washing machine outside in a shed?

Putting white goods into sheds drastically increases the chance of fire. As UKWhitegoods.co.uk states: Washing machines are not designed for outdoor use. Neither are they designed for use in other areas subject to or can be subject to high levels of damp, like bathrooms.

Does outside temperature affect washing machine?

Washing machines are vulnerable to extreme cold as water in hoses and pumps can freeze, leading to potential damage to the water inlet valve and causing leaks when the temperature rises, so it's advised to disconnect water lines when not in use and insulate hoses.

Can I put my washing outside?

It's best to dry your laundry outside in winter

This process takes significantly longer than in summer, but your laundry will dry even in the cold season. As long as the sun is shining and it is dry, you don't have to dry your laundry indoors in winter.

Does a washing machine drain need a vent?

Eliminate Laundry Room Odors with Maplewood's Proper Drain Venting Services. All plumbing fixtures—including washing machines—must be vented.

Where is the best place to put a washing machine?

10 Ingenious Spots to Place the Washing Machine
  • Under the washbasin counter. The bathroom is the obvious choice for the washing machine – the plumbing and electrical points are already in place. ...
  • In the shower stall. ...
  • Under the kitchen counter. ...
  • In the pantry. ...
  • Under an island. ...
  • On the landing. ...
  • Under the staircase. ...
  • In a wardrobe.

How much does it cost to install a washing machine drain line?

Drain pipes cost an average of $225 to $1,200 to install, depending on how easy it is to access the required plumbing. That cost doesn't include the cost of the pipe itself, which ranges from $0.75 to $30 per linear foot.

What happens if roof is not vented?

Excessive Heat in the Attic

With poor ventilation in house, the hot air concentrated at your attic's highest points stays trapped. This, in turn, can lead to uneven roof temperatures (ice dams), an overtaxed HVAC (higher energy bills), and other costly headaches.

Can I run a plumbing vent out the side of my house?

The good news is that your plumbing vent can indeed be run horizontally. When figuring out how to lay the pipes within your walls, it's more important to remember the clearance that is required by your spill line (the point where water overflows a tub, sink, or toilet).

What are the requirements for a washing machine drain?

The drain pipe should be a minimum of 1-1/2" I.D. (inside diameter) to ensure proper draining. The Washer drain hose is a 1-1/4" O.D. (outside diameter). To be confident that no siphoning of water will take place, the drain plumbing must be a minimum of 30" high for Top Load Washers.

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