Drain Contractors vs Plumbers: Who Should You Call?

When you’re dealing with a blocked toilet, slow-draining sink, or a mysterious smell coming from under the floor, the first question that pops up isn’t always what’s wrong; it’s who do I call? This is where the battle between drain contractors and plumbers begins. 

For many homeowners and property managers, the line between plumbers and drain contractors is blurry. Both work with pipes. Both can help when something goes wrong with water. But when the issue is underground or related to your drainage system, calling the wrong professional could cost you more time and money than necessary.

Let’s break it down simply and help you understand when to call a plumber and when to call a drain contractor instead.

What does a plumber actually do?

Plumbers handle the pressurised side of your water system. That means everything to do with bringing clean, fresh water into your home and distributing it to taps, showers, boilers, washing machines, and more.

They also deal with fixtures like toilets and sinks. So if you’ve got a dripping tap, a faulty shower, or a toilet that won’t refill, a plumber is the right person to call. They’re also the go-to when you’re installing new pipework inside a property, replacing a hot water cylinder, or upgrading kitchen plumbing.

But plumbers don’t always specialise in underground work, heavy-duty drain clearing, or complex blockages in external systems. That’s where drain contractors come in.

What do drain contractors do?

Drain contractors focus on the waste side of your plumbing: the system that carries wastewater away from your property and into the mains sewer. This includes everything underground, outside the house, and inside the hidden drainage network.

They’re trained to handle blocked pipes, root intrusions, collapsed drains, cracked soil stacks, and anything that affects the flow of dirty water or sewage. They often use specialist tools like high-pressure water jetting, drain rods, or CCTV inspection cameras to find and fix issues that plumbers aren’t equipped to deal with.

While some plumbers may offer basic drain unblocking, a professional drain contractor is your best bet when the problem goes beyond a simple U-bend or trap.

The key differences explained

Here’s where the distinction really matters. If the problem is with incoming water pipes that bring clean water into your home, it’s a plumbing job. If it’s with outgoing water (pipes that carry waste away), it’s usually a drainage issue.

For example, if your bathroom tap is leaking, call a plumber. If your downstairs toilet keeps backing up when you flush, that’s more likely to be a problem for a drain contractor.

Plumbers tend to work inside the home, with systems that are under pressure. Drain contractors typically work outside or underground, often dealing with gravity-fed systems that carry waste water and sewage.

It’s also worth noting that drain contractors often work closely with emergency response teams and facilities managers. That’s because blocked or damaged drains often need quick action to avoid health risks or property damage.

Real-world examples from FS Group

At FS Group, our engineers are called out every day to resolve problems that plumbers couldn’t fix, or that turned out to be bigger than anyone expected.

In one recent case, a homeowner had hired a plumber to fix what they thought was a blocked toilet. The plumber replaced parts, rodded the trap, and even dismantled part of the bathroom. But the issue kept coming back.

When our team arrived, we ran a CCTV inspection through the drain system and found a partially collapsed clay pipe five metres from the house. It was an underground issue that the plumber never saw. We excavated the damaged section, installed a new PVC pipe, and restored full flow in a day.

Knowing who to call first can save you that entire detour.

What tools do drain contractors use?

Drain contractors rely on a completely different toolkit than most plumbers. One of the most common is the CCTV drain survey camera: a flexible cable with a camera head that can be pushed into underground drains to locate cracks, collapses, roots, or blockages.

They also use high-pressure water jetting to blast away fat, scale, and other debris inside pipes. Unlike plungers or basic rods, jetting fully clears the inside surface of the pipe and restores proper flow.

In bigger cases, they may use excavation equipment or no-dig repair techniques like pipe relining. These aren’t things your average plumber carries in the back of a van.

When should you skip the plumber and call a drain contractor?

Here are a few tell-tale scenarios where you should go straight to a drain expert:

• You’ve got recurring blockages that keep coming back after temporary fixes.
• There’s sewage backing up from a gully or manhole outside your property.
• Water is pooling on your lawn or driveway without a clear source.
• Your property has a strong, lingering sewage smell, especially near drains.
• You’ve tried using rods, chemicals, or plungers, and nothing’s worked.
• Your plumber has already tried without success.

Drainage issues tend to worsen over time. Leaving them unresolved often means more digging, more expense, and more mess. Getting the right person in early can prevent a small issue from becoming a costly emergency.

Can plumbers and drain contractors work together?

Absolutely, and they often do. Many homes and commercial properties have complex plumbing and drainage networks that overlap. In renovations or large repairs, you may need both to work side by side.

For example, if you’re converting a garage into a new bathroom, a plumber will install the new pipework, but a drain contractor may be needed to create new underground connections. Likewise, if a plumber identifies an issue beyond their scope (like a collapsed drain), they may refer you to a drainage specialist.

At FS Group, we often collaborate with local plumbers to support larger repair jobs or ensure that internal plumbing is working properly once the drainage issues have been resolved.

Do drain contractors cost more?

Not necessarily. In fact, when the problem is genuinely drainage-related, calling a drain contractor can save you money. That’s because they’ll have the right tools, diagnostics, and expertise to resolve the issue faster.

Plumbers may charge for time spent investigating a problem they ultimately can’t fix, whereas a drainage team can often diagnose and resolve it in a single visit.

Drain contractors typically charge based on the job or issue, not hourly. Some offer emergency services at higher rates for out-of-hours calls, but you’ll usually get a fixed quote after inspection.

Final thoughts

When things go wrong with water in your home, speed matters. But so does calling the right person for the job. While plumbers are essential for anything involving clean water or internal fixtures, drain contractors are the ones to call when the issue is underground, external, or clearly linked to waste flow.

If you're not sure, a quick call to a reputable drainage company like FS Group can help you figure it out. We’ll ask the right questions and get the right team on the case. Give us a call!