How to Unblock a Drain in London: What to Try, When to Call

Published:2026-08-22

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A blocked drain is more than an inconvenience — left alone it can cause backing up, bad smells and even water damage. Call 020 7183 4810 and we will clear it properly.

Drain blocked or draining slowly?

Fast, thorough drain clearance across London.

Need a Gas Safe engineer today?

Same day callouts across Central and West London, fixed quotes and fully guaranteed work.

Call now — 020 7183 4810   or request a call-back

What usually causes a blockage

  • Grease and fat build-up in kitchen drains
  • Hair and soap build-up in bathroom drains
  • Foreign objects lodged in the pipe
  • Tree root intrusion in outdoor drains
  • A collapsed or damaged section of pipe

Why we do not recommend the popular online fixes

Common online adviceWhy it falls short
“Pour chemical drain cleaner down it”These can damage older pipework and often only clear part of the blockage, so it returns.
“Use a wire coat hanger to fish it out”Can scratch or puncture pipes, and will not clear blockages further down the line.
“Try a plunger repeatedly”Does not resolve tree root intrusion or collapsed pipework, which need proper inspection.

Stop and call us if…

  • Water is backing up or draining very slowly
  • You notice bad smells coming from the drain
  • The blockage keeps returning after clearing it yourself
  • Multiple drains in the property are affected at once

What it costs to wait

A blocked drain left untreated can cause water to back up into the property, damaging flooring and causing hygiene issues, and repeated DIY attempts with chemicals can damage pipework that then needs replacing.

How Olia’s Plumbing & Heating handles it

  1. Call 020 7183 4810 and describe the issue
  2. Our engineer inspects the drain, using CCTV survey where needed
  3. We clear the blockage using proper professional equipment
  4. We flag any wider pipework issues found during the visit

Get your drain cleared properly

Fast call-outs across London.

Book now — 020 7183 4810   or request a call-back

Frequently asked questions

Can I use chemical drain cleaner?

We would not recommend it — it can damage pipework and often does not fully clear the blockage.

How much does it cost to clear a drain?

Call 020 7183 4810 for a clear price based on the type and location of the blockage.

Why does my drain keep blocking?

Recurring blockages usually point to a structural issue like tree roots or a damaged pipe, which needs proper inspection.

Do not risk damaging your pipes with chemicals. Call 020 7183 4810 today.

Related services: Plumber Central London, How to Unblock a Toilet, Guide to Emergency Plumbing Call-outs

About the author
Peyman

Peyman

CEO & Founder — Gas Safe Registered Engineer

Peyman is the founder of Olia's Plumbing & Heating, a London based team with over 15 years of hands on experience in boiler installation and repair, central heating, gas work and emergency plumbing. He personally oversees jobs across Central and West London and writes these guides to help homeowners understand their heating systems.

  • Gas Safe Registered
  • 15+ years experience
  • Covering all of London
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