Sewer Jetter FAQ

Answers to Visitors’ Questions


Q: What size of pressure washer do I need to clean a sewer drain?

A: You an use a broad range of gas and electric pressure washers to unblock a drain. Pressure washers with higher GPM flow ratings can handle larger diameters of drain pipe.

  • Commercial gas-powered pressure washers rated from 3.0 to 4.0 GPM can generally clean pipes up to 6″ in diameter.
  • Residential gas and electric pressure washers rated from 1.3 to 2.9 GPM can generally clean sewer pipes up to 4″ in diameter. This diameter of pipe is commonly used for main household sewer drains.
  • When using an electric pressure washer at the lower end of this GPM flow range, it’s often easier to work from an indoor location so that gravity helps pull the sewer jetter through the line.


Our article about how to unclog a sewer drain with your pressure washer covers this topic in more detail.

Q: What pressure do I need to unclog a sewer line?

A: Virtually any gas or electric pressure washer sold today will deliver adequate pressure to clear a blocked household sewer line. However, to work effectively the sewer jetter’s nozzle and hose should be correctly matched to the PSI pressure and GPM flow ratings of your pressure washer. Our articles about choosing the right sewer jetter nozzle and choosing the right sewer jetter hose cover this topic in more depth.

Q: Where can I buy parts to build a sewer jetter?

A: Our article about building or buying a sewer jetter provides links to parts suppliers. We recommend that you start by selecting a good-quality, US or German-made nozzle.

Q: Can I save money by building a sewer jetter myself?

A: Building a sewer jetter can be an enjoyable experience if you like do-it-yourself projects, but it might cost you more than buying a manufactured unit. Our article about choosing between building or buying a sewer jetter covers this topic in more detail.

Q: Do sewer jetters really work?

A: Visit the Clog Hog website Customer page to see sewer jetter user testimonials and stories.

Q: Can a sewer jetter cut through tree roots?

A: While you can buy special root cutter nozzles for sewer jetters, these are generally designed for pumps with a far higher GPM flow capacity than any residential or commercial pressure washer can deliver.

A sewer jetter attachment for your pressure washer can clear the sediment around tree roots that contributes to drain blockage, but it’s likely that growing tree roots will eventually need to be cleared with a different machine that’s designed for that job.

Q: Can I increase my sewer jetter pressure by reducing the flow?

A: The short answer is no. Your pressure washer is a positive displacement pump that produces the same amount of flow for each revolution of its engine or motor shaft.

Because the gas engine or motor in your pressure washer maintains a nearly constant speed, the GPM flow rate will change very little regardless of pressure – that is, until the pressure exceeds the rating of your machine and the unloader valve shuts off the flow entirely.

While it’s not practical (or safe) to change the flow of your pressure washer, you can build or buy a sewer jetter that makes the most of your machine’s power by closely matching the performance of the jet nozzle and sewer jetter hose to the PSI pressure and GPM flow rating of your machine.

Our article about your pressure washer pump covers this topic in more detail.

Got questions not answered here? Email us.

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