A slow-draining sink is a common household issue that can range from slightly annoying to the sign of a more serious issue. If you notice your sink is taking longer than usual to drain, it’s important that you find out what’s causing it so that you can see whether you can fix it yourself or if you need a plumber. Common causes of a slow draining sink include:
Build-up of debris
Over time, sinks can accumulate a build-up of soap scum, grease, food particles, hair, and other debris.
Blocked U-bend
The U-bend under your sink is designed to prevent sewer gases from coming back up the pipes. However, it can also collect debris, leading to a partial blockage that slows drainage.
Build-up of limescale
In many areas of the UK, hard water is a common issue. Over time, mineral deposits from hard water can accumulate inside pipes, narrowing the passage and restricting water flow.
Poor venting
Plumbing systems need proper ventilation to allow water to drain efficiently. If the vent pipes are blocked, air pressure imbalances can cause slow drainage. This is a less common cause of slow running sinks but can be an issue, especially in older properties.
Issues with the main drain or sewer line
If you notice that multiple drains in your home are slow, or you notice gurgling sounds when draining, the issue might be with the main drain or sewer line. Tree roots, grease build-up, or collapsed pipes can cause these blockages, and will usually need professional intervention.
Diagnosing the problem
If your sink is draining slowly but there is no immediate threat of flooding and you are safe, the first thing to do is see if you can find out the cause by yourself.
- Check for visible blockages – remove the drain cover and inspect for hair, soap scum, or food debris. You might be able to fix the problem by removing any blockages wit gloves or a drain snake.
- Run hot water – pouring boiling water down the drain can help dissolve grease and soap build-up.
- Use a plunger – a sink plunger can create suction to dislodge minor blockages. If your sink has an overflow hole, make sure that you cover it before you plunge so that you can create an effective vacuum.
- Clean the u-bend – place a bucket underneath the U-bend before unscrewing it and cleaning out any debris.
- Use drain unblocker – if none of the above manual methods don’t work, consider using a drain cleaner. In the UK, there are both chemical and eco-friendly enzyme-based options. Try not to rely on using harsh chemicals, as they can damage pipes over time.
If you can’t find or cure the cause of a slow draining sink yourself, or if the problem is becoming progressively worse, it is a good idea to get professional advice. Take a look at our directory of trusted plumbers near you so that you can get the problem sorted with complete peace of mind. Need more help? Follow Trust A Trader on Facebook or Twitter.