A blocked sink drains slowly, or not at all. Kitchen sinks usually block with fat, grease and food scraps, while bathroom basins block with hair, soap and toothpaste.
Fat is the main culprit in kitchens. It looks like liquid when hot, but it thickens as it cools. Scottish Water says fat mixed with other waste can form blockages and fatbergs, so keep it out of the sink.
Let leftover fat cool and set, then scrape it into food waste or the bin. Soup, stock, sauces and milk products also hold fat that can set in drains. A sink strainer will also catch food scraps, because small pieces add up.
The trap under the sink often holds the blockage. Many people can clear it with a bowl and a little care. However, if the pipe beyond the trap is blocked, an engineer may need rods, a snake or a small jetter.
The engineer checks the U-bend or bottle trap for a visible blockage. That shows whether the problem is in the trap or further along the pipe, since the fix differs.
Drain rods, a powered snake or a small jetter can clear the pipe. The choice depends on whether the blockage is fat, scale or debris, because each responds to a different tool.
The waste pipe often ends at a gully outside. Ask the engineer to check it, because debris can collect there and slow the whole run.
Run the tap at full flow to check that the sink drains freely. If it still gurgles, the blockage may not be fully gone.
Prices vary because the type of blockage differs. A kitchen sink with heavy fat may need jetting, which adds to the work. A bathroom basin with hair is often simpler.
Ask for a written quote before work starts, because it shows what is included. Ask whether there is a call-out charge, and ask what the engineer will do if the pipe has a fault, since a damaged pipe changes the job.
Fat and grease are the usual cause, because they thicken as they cool and narrow the pipe. Wipe greasy pans with kitchen roll before washing. Keep fat, oil and grease out of the sink altogether.
They only help with minor blockages, and the fat or scale often stays behind. They do not replace clearing the pipe properly. If the sink still drains slowly, ask an engineer to clear the pipe.
Yes, if the sink shares a waste pipe with other fixtures. A blockage in the shared section can slow a washing machine or a bath as well. If several fixtures are slow, the blockage is probably further along the pipe, since one trap cannot slow them all.