What is hydro jetting?

The system has three core parts: a pump, a high-pressure hose, and a nozzle sized to the pipe. A plumber feeds the hose in through a cleanout, the capped access fitting on the line. Under the International Plumbing Code, drains carry cleanouts near the building drain junction and at sharp changes of direction, which gives a clean entry point for the hose. In a Phoenix slab home that cleanout usually sits outside near the foundation or the property line.

Two numbers control the job: pressure and flow. Pressure, measured in PSI, does the cutting. Flow, measured in gallons per minute (GPM), does the flushing. PSI shears grease and scale off the walls and shaves through root masses, while GPM carries the debris out of the line. A high-pressure, low-volume setup cuts well but moves little material; a balanced machine does both. That is why a jetter rated only on PSI tells you half the story.

The nozzle choice matters as much as the machine. A penetrating nozzle with a tight forward jet drills into a solid blockage first. A flushing or rotary nozzle with wider rear jets then scours the full circumference of the pipe. A chain or cutter-style nozzle is reserved for hard scale and heavy root masses. Switching nozzles lets one rig handle a greasy kitchen line, a root-filled sewer, and a sediment-packed storm drain.

The hose itself is built for the pressure. A reinforced jetter line resists kinking as it rounds bends and feeds dozens of feet down a sewer. Because the rear jets pull the hose forward on their own, the plumber mostly guides and controls feed rate rather than forcing the line in. That self-feeding action is what lets a jetter reach a clog forty or sixty feet from the cleanout and then clean every foot of pipe on the way back out.

A cable machine, often called a drain snake or auger, spins a steel cable with a cutting head down the pipe. It is good at one thing: breaking through a clog fast to restore flow. The catch is what it leaves behind. The cable bores a hole through the obstruction but leaves the pipe walls coated with the grease, soap, sludge, and root hairs that caused the backup. Water drains again, so the line looks fixed, but the buildup keeps narrowing the pipe.

That is why snaked drains so often clog again in the same spot weeks or months later. The root cause is still on the walls. Hydro jetting removes that layer, so the pipe runs at close to full capacity and stays clear longer. Our site has a separate page that compares hydro jetting vs snaking side by side if you want the full breakdown of when each method makes sense.

There is a place for both. A snake is faster and gentler for a simple hair clog in a bathroom sink or a one-time toilet stoppage. Jetting earns its keep on recurring problems, grease, scale, and roots, where clearing the walls is the only way to stop the cycle.

The two methods also pair well. A cable head can chew through a dense root ball or break a solid blockage, and a jetter follows to flush the loosened material and scrub the residue off the walls. On a sewer that has backed up more than once, a plumber will often run a camera, snake if needed to restore flow, then jet to clean the line, and finally re-camera to confirm the pipe is clear. That sequence treats the cause, not just the symptom, which is the difference between a drain that stays open and one that backs up again.

The numbers below are manufacturer and equipment specifications, not plumbing-code requirements. The code governs how pipes are built and accessed, not the PSI a cleaning machine produces. According to the jetter maker Spartan Tool, sewer jetting equipment generally operates in the range of roughly 1,500 to 4,000 PSI, with the exact setting matched to the pipe and the blockage.

In practice, residential drain and sewer work tends to run around 1,500 to 2,500 PSI, which is enough to clear household grease, soap, and small roots without overworking older pipe. Commercial lines, restaurant grease mains, and large-diameter sewers run higher, often in the 2,500 to 4,000 PSI range, because they carry heavier loads and bigger pipe. Flow rises with pipe size too: a small line might need only a few GPM, while a main sewer needs much more water to carry the debris out.

The PSI-versus-GPM balance is the part homeowners miss. As Spartan Tool puts it, "It is important to match the pressure and flow to the application." High PSI with low flow can cut a clog but strand the loosened material in the pipe. Enough GPM is what actually flushes the line clean. A good plumber sets both for the job in front of them rather than running one machine at one setting for every call.

It helps to picture what each number is doing inside the pipe. PSI is the sharpness of the water, the force that lets a thin stream slice grease off the wall and shave a root back to the pipe surface. GPM is the volume behind it, the river that carries those scraps out to the main. Cut without flush and the debris settles a few feet downstream into a new clog. Flush without enough cut and the buildup never leaves the wall. The machine and the nozzle together decide how that pressure and volume are split, which is why matching equipment to the line is a real skill rather than a dial setting.

Hydro jetting is the right call for problems that come back. Grease lines in restaurants and homes, recurring clogs in the same drain, tree roots invading a sewer through joints and cracks, and most commercial drain work all favor jetting because they are buildup problems, not single objects. Grease is the biggest culprit citywide. The EPA's Report to Congress found that grease accounts for 47% of reported sewer blockages, and that blockages cause 48% of sanitary sewer overflows with a known cause. Roots are a contributing factor in about one-quarter of blockage-related overflows. Jetting attacks all three.

There are cases where you should not jet, at least not first. Old, fragile, or already-cracked pipe, including aged cast iron, clay, or Orangeburg, can be damaged by high pressure. The fix there is a camera inspection before any water goes in. A sewer camera shows the pipe's true condition and confirms whether jetting is safe or whether the line needs repair instead. If you see signs of root intrusion, our page on the signs of tree roots in a sewer line explains what to look for, and a restaurant dealing with a commercial kitchen drain overflowing is almost always a jetting candidate once the line is verified sound.

Jetting clears the pipe, but it does not fix a broken one. If a camera finds a collapsed section, separated joints, or a belly that holds water, cleaning buys time at best. The lasting fix is repair or pipe replacement. Used on the right line, though, hydro jetting restores a drain to near-original capacity and is one of the most thorough cleaning methods available for residential and commercial sewers in Phoenix.