How to Locate the Main Drain


It is necessary to be able to find the location of the main because sometimes the sewage line may be clogged and will need to be unblocked. You can easily unblock a clogged drain line if you know the location of the main drain in a house. Any main drain is marked by a sewer clean out point. This pipe allows for plumbers to run augers and other equipment down into the line to maintain the line.

Reasons a Main Drain is Hard to Find

  • You don’t own your home, or have recently bought it.
  • The landscaping hides the drain point.
  • The access point is buried under eroded soil.

How to Locate Main Drain in House

  1. Search for a sewer cap in front of the house. In front of your yard you will probably have sewer caps or clean out points. You are looking for something that resembles a manhole, but quite smaller. Through identifying the sewer caps you can easily trace the location of the main drain points in a house. When the clean out is located you can unscrew it so that you can access the main drain.
  2. Check around the outside of the house in the area where the bathrooms and toilets are located. Some designs of houses will have main drain points outside, immediately where the drainage pipes from the bathrooms leave the house.
  3. Most of the time the access point is outside near the foundation of the home. In rare cases the clean out is through the bathroom floor behind a toilet, so if you still can’t locate it, try there.

Once a clean out is identified then the line can be snaked with an auger or cleaned with a drain jetter. When you move into a new home make it a point to find the sewer clean out access point. It will make plumbing problems more manageable in the future.