How to Unblock a Drain at Home (And When to Call a Professional)

A slow or completely blocked drain is one of the most common plumbing complaints we receive from Sandton homeowners — and it\’s often one you can fix yourself with the right technique and a bit of patience. The key is knowing which methods actually work, which ones can damage your pipes, and when the blockage is serious enough to need professional help.

This guide covers every safe DIY drain clearing method in order of escalation, explains the household products you should never use, and gives you the definitive list of signs that it\’s time to call a licensed plumber.

Understanding Why Drains Block

Before you grab a plunger, it helps to understand what you\’re dealing with. The most common causes of blocked drains in Sandton homes are:

• Kitchen drains: Grease, fat, oil, food scraps and coffee grounds that accumulate over time in the pipe bends (traps)
• Bathroom basin and shower drains: Hair, soap residue and product buildup — often compacted in the U-bend
• Toilet blockages: Wet wipes (even \”flushable\” ones), sanitary products, excessive toilet paper or accidental item flushing
• Outdoor and garden drains: Leaves, roots, silt and debris
• Sewer line blockages: Tree root intrusion, collapsed pipe sections or accumulated grease in the main line — these need professional equipment to clear

Method 1: The Boiling Water Technique (Kitchen and Bathroom)

For grease or soap-based blockages, boiling water is your first line of attack — and it costs nothing. Carefully pour a full kettle of boiling water directly into the drain in three stages, allowing 5–10 seconds between each pour. The heat melts fat and soap deposits, allowing them to flow further down the pipe.

Note: Do not use boiling water on PVC (plastic) pipes. Very old PVC pipe — common in homes built before 2000 — can soften or warp under extreme heat. If you\’re unsure of your pipe material, use very hot (not boiling) water instead.

Method 2: The Plunger (All Drain Types)

A plunger is the most effective and safest DIY tool for most blockages. Use a cup plunger for sinks and showers, and a flange plunger (the one with an extended rubber lip) for toilets.

1. Ensure there is enough water in the fixture to cover the plunger cup — about 5cm is ideal
2. Block any overflow opening (e.g. the overflow hole near the top of a basin) with a wet cloth to create proper suction
3. Position the plunger firmly over the drain opening, sealing completely
4. Pump vigorously 15–20 times with steady, even strokes — maintaining the seal throughout
5. Pull the plunger off sharply on the final stroke to break the seal
6. Test the drain — repeat 3–4 times if needed

Method 3: Bicarbonate of Soda and Vinegar

This classic combination is safe for all pipe types and works well on partial blockages and maintenance flushing. The chemical reaction creates a fizzing action that can break up soft deposits and deodorise drain odours.

1. Pour one cup of bicarbonate of soda directly into the drain
2. Follow immediately with one cup of white wine vinegar
3. Quickly cover the drain with a stopper or cloth to force the reaction downward
4. Leave for 30–60 minutes
5. Flush with a full kettle of hot (not boiling) water

This method works best as part of a regular maintenance routine — once a month on kitchen and bathroom drains — rather than as a solution for a complete blockage.

Method 4: The Drain Snake or Hair Catcher

For hair and soap blockages in shower and basin drains, a flexible drain snake (also called a drain auger) can physically pull the blockage out. These cost R50–R200 at any hardware store and are an excellent investment for Sandton homeowners with long-haired family members.

Insert the snake into the drain, rotate it as you push forward, and then pull back slowly — the spiral end will catch hair and debris. Remove the blockage from the snake and dispose of it in the bin (never back into the drain).

Method 5: Clean the U-Bend (P-Trap)

If other methods have failed, the blockage may be sitting in the U-shaped trap directly under your basin or kitchen sink. This is a sealed loop of pipe designed to hold water (which prevents sewer gases from entering your home) but it also catches debris.

1. Place a bucket under the U-bend to catch water
2. Use a pipe wrench or slip-joint pliers to loosen the slip nuts at both ends of the U-bend
3. Carefully remove the U-bend — water will pour out
4. Clear any blockage from inside the trap using a bottle brush or your finger
5. Check that the rubber washers are intact before reassembling
6. Hand-tighten the slip nuts, then test carefully with cold water

What NOT to Do — Methods That Damage Your Pipes

These approaches are commonly tried but can cause expensive damage to your plumbing:

• Chemical drain cleaners (caustic soda, Drain-O, acid-based products): These work by dissolving organic matter — but they also corrode older metal pipes, degrade rubber seals, and can severely damage PVC. They\’re also highly toxic. We strongly advise against using them in any Sandton home.
• High-pressure hosepipe down an indoor drain: Without professional equipment, this can push the blockage further into the sewer system or dislodge pipe joints.
• Wire coat hangers: The sharp ends can scratch and gouge drain coatings and soft PVC, creating rough surfaces that attract future blockages.
• Repeatedly flushing to \”force\” a toilet blockage through: If the toilet isn\’t draining at all, flushing again will only cause it to overflow.

Signs That You Need a Professional Plumber for Your Blocked Drain

Some blockages are beyond DIY methods — and attempting to force them through can make things significantly worse. Call Sandton Plumbing if you notice any of these warning signs:

• Multiple drains are blocked simultaneously (this indicates a main sewer line issue)
• Gurgling sounds from other drains or your toilet when you use a basin or shower
• Water backing up into the shower when you flush the toilet
• Sewage odour coming from drains even when they appear to be flowing
• The blockage has returned within a few weeks of clearing it
• Water is draining but extremely slowly despite all DIY attempts
• You live in an older Sandton property with original cast-iron or galvanised steel drain lines

Preventing Drain Blockages — Long-Term Habits That Work

The most cost-effective approach to blocked drains is prevention. These simple habits will dramatically reduce blockage frequency in your home:

• Fit mesh drain strainers in all shower and bath drains — empty them weekly
• Never pour cooking oil or fat down the sink — collect it in a jar and dispose of it in the bin
• Run hot water for 30 seconds before and after washing greasy pans
• Flush only toilet paper — no wet wipes, cotton wool, sanitary products or facial wipes
• Do a bicarbonate and vinegar flush on all drains once a month
• Have a professional drain inspection every 3–5 years in older Sandton properties

Professional Drain Unblocking Services in Sandton

When your drain blockage is beyond DIY, Sandton Plumbing offers complete drain clearing and sewer services across the Sandton area. Our equipment includes high-pressure water jetting machines capable of clearing the most severe blockages, and CCTV drain inspection cameras for diagnosing deep or recurring problems in your sewer lines.

We service all suburbs across Sandton CBD, Bryanston, Morningside, Hyde Park, Rivonia and beyond. For full details on what we offer, visit our Blocked Drains & Sewer service page.