Water is coming out of our what I assume is a stink pipe. We live within city limits. This is located in our basement. City says we have no exterior clean out. We plan on calling to have this pipe snaked out and hope that is the issue. Any suggestions what else it could be?

enter image description here

  • On the right is your hot water heater pop off valve? On the left what is the pipe hooked to? – Kris Dec 29 '17 at 14:52
  • Or is that a condensate drain from air condition on the right? – Kris Dec 29 '17 at 14:56
  • 3
    Not sure what a "stink pipe" is, but I'm surely not going to google it to find out. – Tester101 Dec 29 '17 at 15:00
  • Is that P-trap connected right to the end of the main sewer line, or does the sewer line go down in the wall? – Tester101 Dec 29 '17 at 15:01
  • @Tester101 Appears to be another name for a vent stack – Machavity Dec 29 '17 at 15:28

We live within city limits.

Depending on where you live, the sewer system may be tied into the storm drain system. When you get enough water in the system, it can back up into the sewer line in your house

A sewer backflow valve can prevent waste water backups, particularly from a public sewer. But before we get into the details and benefits of a sewer backwater valve, let’s explain what backwater is. Sewer backflow is a term used in plumbing for unexpected and unwanted flow of water in reverse direction. Normal plumbing allows wastewater to flow from a home to the city sewer, but backflow is the exact opposite.

When backflow happens, there can be a serious health risk due to contaminated waste water entering your premises. Backflow occurs when the municipal drainage system or city sewer overflows, and sends water back through a sewer pipe into your home. Immediate proper clean-up is required to prevent risk of disease and further damage to property.

You might be experiencing what that article terms a "sewer surcharge", but on a smaller scale. If you do not have a backflow valve installed (and most homes do not), the sewage can back up into your house. Even if this is not the issue here, I would check to make sure you have one installed.


So it appears that this setup has been in place for a while. Presumably with no problems. So what changed recently that could cause the not so perfect setup of drains p traps and condensate drip lines to fail?

1 something has plugged the drain line

2 something is obstructing air admittance into the stink pipe

3 you have increased the gpm of discharge into the drain and it can’t handle the larger quantity of water and the higher flow rate.

New washing machines can have much faster and stronger discharge from pump than older ones did. I had a customer that bought a new one and the old drain line that never gave any trouble was just to small and could not get rid of water as fast as the washer was pumping. I had to increase the pipe size of the drain assembly from the washer to the main sewer line in the house.

Below is a diagram of a typical up to code washer drain set upenter image description here

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