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How Do I Unclog a Main Drain?

Clogged Main Sewer Drain

If several plumbing fixtures in different rooms won't drain, you could have a clogged main drain. To clean your main sewer drain:

  1. First, find the right drain opening to reach the clog.
    • A main drain cleanout could be your best choice, since it's usually easiest to feed the drain cleaner uphill through the cleanout, toward a problem area under the building, or downhill toward a problem area in the yard.
    • Unclog a Main Sewer DrainThe main drain cleanout is often located outside, around two feet from the building foundation, in a line that runs from your building to the city drain or septic tank. If the building has a basement, the cleanout could be there. Outdoor cleanouts can sometimes be hidden by shrubs, or buried by soil that was added after construction.
    • Newer homes could have additional cleanouts on exterior and interior walls. These secondary cleanouts can be a good choice if they feed downhill toward the problem area.
    • If you can't locate the main drain cleanout or can't use it to reach the problem area, you can try to feed the drain cleaner through a clogged indoor drain opening like the opening under a sink, a clean out opening in a wall, or a shower floor drain. If feeding the drain cleaner through an indoor drain opening, that drain opening must be clogged so that the drain cleaner can reach the problem area.
  2. Needle Nose Drain CleanerNext, choose the right drain cleaner.
    • Consider using a sewer jetter to clean a main drain, since it can help scrub off sticky residue on pipe walls and flush away sediment so fewer clogs come back.
    • A Needle Nose™ drain cleaner is a sewer jetter with a tougher, braided steel jacket and a special compact nozzle tip that allows it to pass through more types and sizes of drains.
    • Needle Nose Drain CleanerTo clean your main sewer drain from an outdoor cleanout:
    • Put on fluid resistant work gloves and eye protection. Use extra care if you believe the pipe could contain drain cleaning chemicals.
    • Main Drain CleanoutConnect the drain cleaner to your pressure washer trigger gun, start the pressure washer, and then guide the nozzle at least a foot into the drain opening, taking care to feed the nozzle in the direction of the clog, before you start the flow of water.
    • Guide the sewer jetter into the pipe as you squeeze the trigger. For more thorough cleaning, every few feet pull back about halfway and then continue moving forward.
    • If you're feeding the sewer jetter uphill, listen for a surge of fluid as the clog clears, and then move a foot or two back from the drain opening to avoid any splashing liquid.
    • After you have finished cleaning the drain, pull the sewer jetter out. Use care to release the trigger to stop the flow of water before the nozzle reaches the drain opening. Then replace the drain cover.Clog Hog Sewer Jetter Video
    • For more details you can watch this 3 minute video.
    • Note: you should avoid using a sewer jetter in these cases:
    • If you think that your sewer drain could have structural problems, or if your property has foundation issues or there are symptoms such as sticking doors and cracking walls, you should hire a licensed plumber to inspect the drain so you'll be sure that a drain cleaner won't get stuck in any large crack or breach in the line.
    • If you think that the clog could be caused by tree roots, and you're sure that the drain is in good physical condition, consider renting a large mechanical drum auger with a root cutting blade to clear the line.
    • If you live in an older home that could have ceramic (clay) or Orangeburg (wood composite) drains, you should hire a licensed plumber to inspect the drain before cleaning since these types of drains are more likely to clog because of cracks, breaches and structural issues.
  3. If you're not comfortable performing one of these steps, hiring a good, licensed plumber could save you money in the long run. To find a good plumber in your area:Licensed Plumber
    • Start by asking family, friends and co-workers to recommend a licensed plumber who has performed similar services for them.
    • If you are unable to find a good recommendation from someone you know, search local directories like Google Maps, Yelp and CitySearch for licensed plumbers nearby who have good online reviews. Don't always trust reviews from individuals who published very few other reviews, or from people who give only positive reviews to everyone. Be aware that good service providers sometimes get a small number of negative reviews for reasons that might not be relevant to your situation. Look for a company with several reviews that tell a positive, believable story about repairs that are similar to yours.
    • After you find one or more licensed plumbers who seem to have a good reputation, search online for the company name and the names of individuals at the company, if known. Take into account both the positive and negative information that you find about the company.
    • Be aware that good plumbers sometimes have a backlog of several days during peak times when there are low temperatures, heavy rainfall or holidays. Sometimes heavy demand can be a sign of a company with lots of repeat customers.

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