What is hydro jetting?

High-pressure water jetting that uses sustained flow to cut through roots and grease and flush debris clear of the pipe — far more thorough than a hand-held drain snake.

What does 5,500 PSI mean for clearing a drain?

It is the cutting pressure; paired with 28 litres per minute of flow it can cut established root masses and flush the material away rather than leaving it to reaccumulate.

Is hydro jetting better than a drain snake?

For most blockages, yes — a snake often punches a hole through and leaves debris, while jetting cleans the full pipe wall. A snake still suits some access points.

When is hydro jetting not enough?

When the pipe is cracked, collapsed or root-damaged. Jetting clears it, but a CCTV inspection is needed to find the cause and a reline or repair to fix it permanently.

High-Pressure Water Jetting: How Hydro Jetting Clears Blocked Drains (and When It's Not Enough)

Christopher Unwin
May 2
4 min read

Updated May 2026 — Around The Clock Plumbing Pty Ltd, Oakleigh South.

High-pressure water jetting — also called hydro jetting — is the professional standard for clearing blocked drains. Unlike a hand-held drain snake, which pokes a hole through a blockage and leaves debris behind, a water jet uses sustained high-pressure flow to cut through root masses, break up grease and fat accumulation, and flush all debris clear of the pipe. This guide explains how it works, what the numbers mean, and when jetting is the right tool versus when a deeper diagnostic is needed.

How High-Pressure Water Jetting Works

A hydro jet unit pumps water from a tank through a hose fitted with a specialised nozzle, which is fed into the drain. The nozzle has forward-facing jets to cut through the blockage and rear-facing jets that propel the head through the pipe while simultaneously flushing debris back toward the access point. The combination of pressure and flow rate is what makes it effective — pressure alone cuts; flow clears.

ATC Plumbing operates a Bar Group unit rated at 5,500 PSI and 28 litres per minute. That combination of pressure and flow is sufficient to cut through established root masses in residential and light commercial drains — not just surface debris — and to flush the cut material clear rather than leaving it to reaccumulate downstream.

What 5,500 PSI Actually Means in Practice

Pressure is only one part of the equation. A common misconception is that higher PSI always means better performance. In drain jetting, flow rate (litres per minute) is equally important — it determines whether debris is actually transported out of the pipe once cut. A high-pressure unit with low flow will cut root material but may not move it far enough to clear the blockage completely.

Domestic jetter units typically run at 1,500–2,500 PSI and 8–12 L/min — adequate for grease and light debris in household drains.
Professional units like ours at 5,500 PSI and 28 L/min handle heavy root infiltration, compacted debris and commercial grease deposits that domestic units cannot shift.
Truck-mounted jetting rigs (used for larger council or main-line work) operate at significantly higher flow rates again — different application, not the same job.

When Jetting Is the Right Tool — and When It Isn't

Hydro jetting is the right first response for most drain blockages — particularly where grease, debris accumulation or light root intrusion is suspected. It's fast, thorough, and leaves the pipe interior clean rather than just punched through.

Where jetting is not the complete answer is in drains with a structural problem: a cracked or collapsed pipe section, a significant joint offset, or a root entry point that will simply regrow. In these cases, jetting clears the blockage but doesn't fix what's causing it — and the drain will block again. This is why we follow recurring blockages with a CCTV camera inspection: fast arrival and jetting clears the immediate problem, then accurate diagnosis via camera finds the underlying cause, then a permanent fix — relining or targeted repair — ends the cycle.

Hydro Jetting vs Drain Snake: The Key Differences

A drain snake creates a hole through the blockage. Jetting removes the blockage and cleans the pipe wall — significantly reducing the chance of rapid reblocking.
A snake cannot remove grease and fat that has adhered to the pipe wall. High-pressure flow scours the wall surface.
Jetting is more effective for root masses — the high-pressure forward jets cut through root material that a rotating snake cable would struggle to penetrate.
A snake may be preferable for very fragile older pipes where high-pressure water could cause further damage — this is assessed on-site before jetting begins.

Common Questions About High-Pressure Water Jetting

Will high-pressure jetting damage my pipes?

In sound pipes, no. The pressure is calibrated to clear blockages, not damage pipe walls. For older clay or deteriorated pipes, we assess condition before applying full pressure — and a CCTV inspection beforehand removes any guesswork.

Can jetting remove tree roots permanently?

Jetting cuts tree roots present in the pipe but doesn't prevent regrowth — roots will return through the same entry point. A permanent solution requires sealing that entry point, either via CIPP pipe relining or targeted pipe repair.

What is the difference between PSI and flow rate in a jetter?

PSI (pounds per square inch) is the pressure that cuts through the blockage. Flow rate (litres per minute) is what flushes debris clear of the pipe. Both matter — a high-PSI, low-flow unit cuts but doesn't clear. Our Bar Group unit at 5,500 PSI and 28 L/min delivers both.

Do you provide a fixed-price quote before jetting?

Yes — we quote before starting work. No hidden call-out fees, no surprises. If a CCTV inspection is recommended after jetting, that's quoted separately and explained clearly before proceeding.

Written and reviewed by Christopher Unwin — founder, Around The Clock Plumbing Pty Ltd, Oakleigh South. BPC Licence #50694, Type A gas, 22 years' experience. National Council member, Master Plumbers Australia & New Zealand.

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