What happens if a drain doesn’t have a vent?
Without a vent to allow pressure to escape from the plumbing system, harmful sewer gases can build up and make it difficult for water to move through the pipes efficiently. A clogged plumbing vent creates problems not because it doesn’t allow air in, but because it won’t let it out.
How far can a drain line run without a vent?
For pipes that have a diameter of 3 inches the distance is 6 feet and for a 4-inch pipe the most it should be away from the vent is 10 feet. Keep in mind that toilets have their own traps so there is no need to have one on the drain line, but it still must have a vent.
How do you vent a washing machine drain line?
The best way to vent a washing machine drain pipe is to run it into an existing plumbing vent stack. If this is not possible, you can install a separate vent stack. Either way, it’s important to ensure that the vent stack is properly sized and installed to prevent future problems.