What Actually Is Drain Jetting?

Drain jetting — also called hydro-jetting or high-pressure water jetting — is exactly what it sounds like. A specialist pump unit forces water through a hose at pressures between 1,500 and 4,000 PSI, and that water exits through a nozzle inside your drain pipe. The nozzle is designed with backward-facing jets that propel the hose forward while blasting the inside walls of the pipe with a concentrated stream of water.

It’s not the same as the pressure washer you use to clean your patio. A drain jetter delivers a much higher volume of water at sustained pressure, and the nozzles are engineered to cut through solid blockages — not just rinse them. The water scours the pipe walls, breaks up grease and scale, flushes out debris, and carries everything downstream into the main sewer. When it’s done, the pipe is clean from wall to wall, with the full internal diameter restored.

Compare that to drain rods, which just push a blockage through — if they can get through it at all. Rodding can temporarily clear a path for water, but it leaves the pipe walls coated in grease and scale, and the blockage often reforms in the same spot within weeks. Jetting cleans the pipe. Rodding just postpones the problem.

Why Croydon’s Drains Need Jetting More Than Most

Croydon has one of the most varied drainage networks in South London, and that variety creates specific problems that jetting is uniquely good at solving.

The old town centre. Central Croydon — around the High Street, George Street, and the Whitgift Centre area — sits on a network of Victorian brick sewers that are over 140 years old. These are egg-shaped brick tunnels, not round pipes, and they were designed for a population a fraction of the size. The brickwork is rough, which means debris catches on the surface and builds up over time. Scale — a hard, calcified deposit that forms inside old drains — is a massive problem in these sewers. It narrows the pipe diameter gradually over decades until what was once a 9-inch sewer is effectively a 4-inch pipe. Jetting is the only non-dig method that can remove scale. Rods just bounce off it.

The suburban spread. Outside the town centre, Croydon is a patchwork of Victorian terraces in areas like Thornton Heath and South Norwood, 1930s semis in Shirley and Sanderstead, and post-war estates in New Addington and Fieldway. The 1930s properties are a particular problem — they were built with salt-glazed clay pipes that are now approaching 100 years old. These pipes develop rough internal surfaces over time as the glaze wears away, and they’re prone to root ingress from the mature trees that line so many Croydon streets. A jetting nozzle with a root-cutting attachment can shear through roots and flush them out, restoring flow without needing to excavate.

The commercial factor. Croydon has one of the largest commercial centres in the South East outside central London. The restaurants, cafes, and takeaways around the High Street, Surrey Street Market, and the Boxpark development generate huge amounts of cooking oil and grease. When that grease hits the drains — even with grease traps in place — it cools, solidifies, and combines with other debris to form fatbergs. A fatberg in a Croydon drain is not something a set of rods can handle. It needs a jetter with a penetrating nozzle to break it up and flush it through.

When Should You Call for Drain Jetting?

Not every slow drain needs jetting. Sometimes a simple blockage can be cleared with rods or a plunger. But there are clear signs that you’ve moved past the simple stage and need the big guns.

• Recurring blockages. If you’re clearing the same drain every few months, rods aren’t fixing the root cause. There’s a buildup of grease, scale, or roots inside the pipe that keeps catching debris. Jetting removes the buildup entirely.
• Multiple drains affected. If the kitchen sink, the toilet, and the shower are all slow or backing up, the blockage is in the main drain — the pipe that carries everything away from the house. That pipe is usually 4 to 6 inches in diameter and buried under the garden or the driveway. Rods can’t handle that distance reliably. Jetting can.
• Bad smells. A persistent smell of sewage or stagnant water around your drains means waste is sitting in the pipe. Jetting flushes it out and cleans the pipe walls so nothing is left to smell.
• After a CCTV survey. If you’ve had a CCTV drain survey and the footage shows scale buildup, root ingress, or heavy silt deposits, jetting is the recommended next step. The survey tells us exactly what we’re dealing with, and we can choose the right nozzle and pressure for the job.

The HydraFlow Approach to Drain Jetting in Croydon

We don’t just turn up with a jetter and blast away. That’s how you damage old pipes. Here’s how we do it properly.

Step one: assess. We start with a CCTV survey unless the blockage is so severe that water is backing up into the property — in which case we clear the immediate blockage first, then survey afterwards. The camera tells us the pipe material, the diameter, the type and location of the blockage, and the condition of the pipe walls. That information determines the pressure setting and the nozzle choice.

Step two: choose the right nozzle. Different blockages need different nozzles. A penetrating nozzle focuses the water into a single forward jet to punch through a solid blockage. A rotating nozzle spins the water jets in a 360-degree pattern to scour the pipe walls clean. A root-cutting nozzle has hardened steel teeth that shear through roots while the water flushes the debris away. A chain flail nozzle uses spinning chains to break up hard scale. We carry all of them and we use the one that matches the problem.

Step three: jet at the right pressure. Old clay pipes in Croydon’s Victorian and 1930s properties can’t take the same pressure as modern PVC pipes. We adjust the pressure to match the pipe material — high enough to clear the blockage, low enough not to damage the pipe. A 1930s salt-glazed clay pipe in a Shirley semi gets a different treatment than a modern plastic pipe in a Purley development.

Step four: verify. After jetting, we run the CCTV camera through again to confirm the pipe is clean and clear. We show you the before-and-after footage so you can see the difference. No guesswork, no “that should be fine now.”

Drain Jetting vs. Other Methods — What’s the Difference?

There’s a lot of confusion about what different drain cleaning methods actually do. Here’s the short version:

• Drain rods — a set of flexible rods screwed together and pushed into the drain. They work for simple, soft blockages close to the access point. They don’t clean the pipe walls. They can’t handle roots, scale, or fatbergs. They snap easily in old clay pipes.
• Chemical drain cleaners — caustic or acidic liquids that generate heat to dissolve organic matter. They’re dangerous to handle, they can damage old pipes, they don’t work on full blockages, and they create a hazardous sludge. We don’t recommend them for anything.
• Electro-mechanical cable (“drain snake”) — a rotating cable with a cutting head. Good for roots. Less good for grease, scale, or silt. Can damage old pipes if used aggressively.
• Drain jetting — high-pressure water that cleans the pipe from wall to wall. Removes grease, scale, roots, silt, and debris. Restores the full pipe diameter. Safe for all pipe materials when used at the right pressure. The gold standard.

If you’ve tried rods or chemicals and the problem came back, you need jetting. If you’ve got roots in your pipes, you need jetting with a root-cutting nozzle. If you’ve got a fatberg, you need jetting. If you want the problem fixed properly the first time, you need jetting.

Areas of Croydon We Cover

We cover the whole London Borough of Croydon — from the town centre out to the edges. That includes Addiscombe, Ashburton, Broad Green, Coulsdon, Kenley, New Addington, Norbury, Purley, Sanderstead, Selsdon, Shirley, South Croydon, South Norwood, Thornton Heath, Upper Norwood, Waddon, West Croydon, and Woodside. Each area has its own drainage quirks — the Victorian terraces of Thornton Heath have different problems than the 1930s semis of Sanderstead, and the post-war estates in New Addington have different pipe materials again. We know the area and we know what to expect.

Posted by HydraFlow — drainage and plumbing specialists covering London. We provide blocked drain clearance, CCTV drain surveys, high-pressure drain jetting, and emergency drainage services across Croydon and South London.