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What should you do about a blocked sink?

A blocked sink means water sitting in the basin instead of leaving, and the useful post says which fittings are slow and whether anything else in the house is affected. This guide does not tell you to open the trap or to pour a chemical down it.

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By the QuoteZila editorial team. Editorial policy.

What counts as a blocked sink?

The water goes into the basin and does not leave, or it leaves so slowly that the basin fills while you wash. That is the whole definition this page will use. It is not a noise in the loft, which is a trickling sound. It is not a puddle on the lawn, which is garden drainage. It is not a pan that will not flush, which is toilet repairs.

Crewe, Nantwich and Sandbach are the first towns. Anyone in the UK can post or register.

What should you write in the job?

Say which basin: kitchen, utility, or a bathroom basin. Say whether a dishwasher or a washing machine shares the waste, if you know. Say whether the bath, the shower or another basin is also slow. Say whether water comes back up when something else empties. Say whether you can see a blockage at the plug hole, such as food or hair, without putting a tool in.

If you have already tried a plunger, say that, and say whether anything changed. This guide does not teach a plunging method and does not promise one will work. Do not pour a chemical cleaner in because a bottle suggests it. This page does not describe any product, and a chemical left in a pipe is something the plumber then has to work around. If you have already poured one, say so, so they can take care.

Do not undo the trap. Do not rod the waste from inside the house with a borrowed tool. Describe, then hire.

Who should you ask?

WaterSafe Register describes itself as a free online directory of plumbers and water supply pipe installers that can be searched [S1]. Plumbers are the trade. A kitchen fitter is the wrong first call unless the sink is part of a new kitchen you are already having fitted. Say if the blockage started the day a new appliance was connected. That fact belongs in the first line.

Citizens Advice says some traders charge for quotes, so ask about this first [S2]. A blocked sink is often a visit rather than a large fixed build. Ask whether the price is for clearing one basin, and what happens if the blockage is further along. A quote is a fixed price and an estimate is a rough guess, so ask which you are being given [S2]. For a larger job, such as a waste run to be replaced, try to get written quotes from at least 3 traders [S2]. Materials, if any pipe is replaced, should be a separate line [S2].

What is not part of this visit?

A new supply pipe in plastic is PEX pipe. A header tank is a header tank. If the sink is blocked and the ceiling is also stained, say both: the waste might be leaking as well as blocking, and the ceiling is a plasterer's question after the water has stopped. The plumber cost guide is the wider page for a plumbing visit. This one stays with the waste that will not leave.

GOV.UK lists installing a bathroom that will involve plumbing among work that might need building regulations approval [S3]. Clearing a blockage is not that sentence. Replacing a run of waste as part of a new bathroom might be. If your job grows from "clear the sink" to "replace the bathroom wastes", say so, and ask whether building control is involved [S3]. Building regulations approval is different from planning permission [S3]. GOV.UK: building regulations approval. QuoteZila is not affiliated with this organisation. The page is building regulations approval.

If the house is listed, do not chase a new waste through a listed wall without asking the authority. GOV.UK says works that affect the character of a listed building require listed building consent [S4]. A plunger-scale clear-out is not that. A new pipe through an old wall might be.

Jobs you might post

These are examples, not taken from real job posts.

  • "Kitchen sink fills and will not empty. Dishwasher on the same waste. Bathroom basins are fine. I have not taken the trap off and I have not used a chemical."
  • "Bathroom basin slow, bath is slow too. Please look at more than the one trap. Quote the clear-out, and say if you think pipe has to be replaced."
  • "Sink blocked since a new washing machine was fitted last week. Please check that connection. No other work."

How should you read the price?

Ask whether a figure to have a look is a fixed quote or an estimate. A quote is a fixed price and an estimate is a rough guess [S2]. Ask what is included if the first look fails. A business registers for VAT when taxable turnover for the last 12 months goes over £90,000 [S5]. A small clear-out may or may not show VAT. Ask, and do not treat the tax threshold as a call-out price. This guide does not print one.

Up to five matched local businesses can send a quote [QZ2]. QuoteZila is free for customers and local businesses [QZ1].

Honest status: QuoteZila is new. We're starting in Cheshire, beginning with Crewe, Nantwich and Sandbach, and growing area by area. Anyone in the UK can still post a job or register a business. How fast you get quotes depends on how many local businesses have joined near you. Businesses can register and receive jobs straight away. We don't check insurance, qualifications or registrations, so please check these yourself before you hire.

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Is a blocked sink the same as a trickling sound?

No. A trickle you can hear when the taps are off is water moving when you have not asked it to. A blocked sink is water that will not leave. If you have both, say both. They are not one fault just because they are both wet.

Should I take the trap off?

This guide says no. Undoing the trap under a basin can spill foul water and can leave a joint that weeps after you have put it back. Tell the plumber whether the trap is the bottle type or the bend type if you can see that without tools. If you cannot, say you have not looked closely.

What if the bath and the basin are both slow?

Say so in the first line. One basin can be a local blockage. Several fittings slow together can be further along the waste. The plumber needs that difference before they price a look at one trap only. This page does not name the further point.

Is the garden drain the same visit?

Only if you say the outside gully is part of the problem. Standing water on a lawn is a different page. A kitchen sink that will not empty is this one. Do not combine them into a single vague 'drainage' price unless you describe both.

Does QuoteZila check plumbers?

No. We don't check insurance, qualifications or registrations, so please check these yourself before you hire. You can report a quote or a business from your job page.

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Sources

  1. QZ1: QuoteZila product fact. QuoteZila pricing line.
  2. QZ2: QuoteZila product fact. QuoteZila FAQ How does getting quotes work.
  3. S1: WaterSafe Register, WaterSafe. Accessed 2026-10-29. https://www.watersafe.org.uk/
  4. S2: Before you get work done on your home, Citizens Advice. Accessed 2026-10-29. https://www.citizensadvice.org.uk/consumer/getting-home-improvements-done/before-you-get-building-work-done/
  5. S3: Building regulations approval, GOV.UK. Accessed 2026-10-29. https://www.gov.uk/building-regulations-approval
  6. S4: Conserving and enhancing the historic environment, GOV.UK. Accessed 2026-10-29. https://www.gov.uk/guidance/conserving-and-enhancing-the-historic-environment
  7. S5: Register for VAT, GOV.UK. Accessed 2026-10-29. https://www.gov.uk/register-for-vat