A common household hack for dealing with a slow or blocked kitchen sink is causing more harm than good, a leading plumbing expert has warned. The practice of pouring boiling water down the plughole to shift grease and food debris is a frequent cause of serious pipe damage and deeper blockages.
The Festive Plumbing Crisis
Ankit Sehgal, who runs the drainage company Swiftdrain, reports that the period following Christmas is one of their busiest for emergency call-outs, with many linked directly to this well-intentioned error. "People assume boiling water will melt fat and solve the issue instantly," Sehgal explained. "In reality, it often pushes the problem deeper into the pipework and damages the pipes at the same time."
He detailed the process: the hot water may liquefy the grease initially, but as it travels and cools, the fat solidifies again much further along the drainage system. This creates a thicker, more stubborn blockage that is harder to reach and remove than the original one. "Each time you do it, you're layering more fat further down," Sehgal cautioned. "Eventually, the pipe becomes almost completely blocked."
Hidden Damage to Your Pipes
The risk isn't limited to worse blockages. A significant number of UK homes have plastic piping, particularly under kitchen sinks where grease is most common. Scalding water can soften these plastic pipes, weakening their joints and potentially causing small, unnoticed leaks.
"Boiling water can soften plastic pipes, weakening joints and causing small leaks," Sehgal warned. "Those leaks often go unnoticed until serious damage has occurred to cabinetry or flooring, leading to costly repairs."
Expert Advice for Prevention and Cure
The best strategy, according to Sehgal, is prevention. He strongly advises households to never pour cooking grease or fat down the drain and to scrape plates thoroughly into the food waste bin before rinsing.
For dealing with early signs of a slow drain, he recommends a safer, effective alternative: a mixture of warm (not boiling) water and a small amount of washing-up liquid. "If you notice slow drainage, stop using the sink heavily," he said. "Continuing to add waste only makes the blockage grow."
Persistent problems, however, require professional attention. Key warning signs that you should call a plumber include:
- Ongoing slow drainage despite home remedies.
- Gurgling noises coming from the plughole.
- Unpleasant odours emanating from the drain.
"Once these warning signs appear," Sehgal concluded, "there's not much you can do at home to properly fix them. Trying drastic measures often just increases the final repair bill."
