A blocked sink leaves dirty water in the basin. Kitchen sinks clog with grease and food waste, while bathroom basins clog with hair and soap. The blockage often sits in the trap under the sink. Because the trap is close, it is the first place to look.
Grease is the main culprit in kitchens. It cools inside the pipe, then sets and narrows it. Because of this, hot water alone may only move the problem along. A strainer in the plughole can still help a lot.
Engineers clear sinks with rods, a drain snake or a small water jet. They may also check the outside gully where the waste pipe ends. If the sink drains but gurgles, a shared pipe may be at fault. However, a quick check of the trap often comes first.
Price depends on the type of blockage and how far along the pipe it sits. Grease in a kitchen waste pipe can take more work than hair in a basin. However, if the engineer finds damage, the job may change. Ask for a written quote first, and ask what happens then.
Grease and food waste build up in the waste pipe. Even a little oil sets as it cools. A sink strainer and wiping greasy pans before washing both help. Since the build-up is slow, small habits add up.
Chemical cleaners may shift a minor blockage, yet they can harm old pipes and seals. Never mix products, and follow the label. If the sink stays blocked, ask an engineer rather than adding more. Repeat doses can still do harm.
Yes, if the waste pipe joins a shared run. A blockage in the shared part can slow other fixtures too. If several fixtures drain badly, the problem is probably in the shared pipe. Because of that, a single trap clean may not fix it.
This page sits under blocked drains, which covers the wider picture. For local details, see the pages for blocked drains in Plymstock and blocked drains in Torpoint, since each town has its own page. You can also read How to Prevent Blocked Kitchen Drains: A Practical Guide for a wider guide.