How to vent a sink Every sink needs a sink vent. A plumbing fixture like a sink can not function properly without a sink vent. When a drain pipe drains it creates a negative pressure in the sink drain, the negative pressure will pull the water out of the ptrap of the sink thats draining and sewer gases can enter your home if a sink vent is not installed. There are several different ways in which to install a sink vent at home even if you want to install a sink vent on an existing sink. A sink needs a vent because the pressure put on the drain pipe when water flows down the drain pipe needs to equalize. The air needs to escape the drain pipe in order for the sink to vent.
The best way to think about a sink vent is if you were to hold a pop bottle upside down and dump it out, it glugs out. add a whole to the top of the bottle and it pours out, that is a sink vent.
How To Vent a Sink
How to vent a sink? There are 3 ways to install a sink vent that we will go over. The three different ways to install a sink vent are
- Back Venting a Sink Vent
- Continuous Waste and Vent
- Using an Air admittance Valve/ Cheater Sink Vent
Back Venting a Sink
|Back Venting a Sink|
When back venting a sink the vent is takin off the horizontal portion of the drain pipe for the sink. The sink vent must be installed within 4’11″ from the ptrap (trap weir) that serves the kitchen sink drain pipe. The sink vent must also be installed “nominally vertical” when put into the horizontal drain pipe or in other words greater than 45 degrees. The sink vent must also tie into another vent above the sink rim.
- Sink Vent must be installed within 4’11″ of the ptrap
- Sink Vent must be installed either vertically or above 45 degrees.
Continuous Waste and Vent
|Continuous Waste and Vent|
Installing a continuous waste and vent for your sink vent is a preferred way of installing a sink vent. The sink vent ties into a vertical drain pipe that allows the liquids from the drain pipe to exit down the vertical portion of the pipe while the air moves up the top of the vertical pipe. The sink vent must be tied in within 4’11″ from the ptrap serving the sink. When adapting the horizontal drain pipe to the vertical pipe a TEE fitting must be used not a WYE.
- The sink vent must be tied in within 4’11″ from the ptrap serving the sink.
- When adapting the horizontal drain pipe to the vertical pipe a TEE fitting must be used not a WYE.
Air Admittance Valve / Cheater Vent
|AAV / Cheater Vent for kitchen sink|
When there is no option to install a back vent or a continuous waste and vent an air admittance valve or a cheater vent as it has been slanged can be installed. The AAV / cheater vent allows air into the drain pipe when the sink drains. The negative pressure caused by the liquids going down the drain pulls a check valve open in the cheater vent and allows air into the drain pipe equalizing the pressure. A cheater Vent must be Certified, do not cheap out on this device when a cheap cheater vent fails it lets sewer gas into your home. The cheater vent must be installed within 4’11″ of the ptrap serving the sink.
- A cheater Vent must be Certified
- The cheater vent must be installed within 4’11″ of the ptrap serving the sink.
Where To Buy a Cheater Vent
|Sink Drain Kit with Cheater Vent $31.48|
A cheater vent can be purchased online the cheapest. Below are the best deals we could find on buying a cheater vent online. All of these cheater vents are certified or approved by a safety comity.
Related Plumbing How To Articles