How to Choose a Plumber in London — The Complete Guide

The most reliable source remains personal recommendation — a neighbour or friend who has had recent plumbing work is worth ten Google searches. When personal recommendations are not available, the best online sources are WaterSafe (the national directory of approved plumbers, backed by water companies) and the Chartered Institute of Plumbing and Heating Engineering (CIPHE) directory. Both require verified qualifications. General trade platforms (Checkatrade, MyBuilder, Bark) have variable quality — the review system helps but does not replace vetting. Local property services companies like Hampstead On Demand have qualified specialists and know the local housing stock. Avoid the first Google result for "emergency plumber" — these are often aggregator sites that dispatch the cheapest available operative, not a qualified tradesperson.

For any gas work — boiler service, gas pipe work, appliance installation — Gas Safe registration is a legal requirement. The Gas Safe Register is the official list of businesses and engineers qualified to work on gas appliances in the UK. You can verify any engineer on GasSafeRegister.co.uk or by calling 0800 408 5500. For general plumbing (cold water, hot water, drainage), there is no legal requirement — but WaterSafe registration and CIPHE membership indicate a plumber who has committed to professional standards. WIAPS (Water Industry Approved Plumber Scheme) certification is required for certain water regulation work. When a plumber is handling both plumbing and gas work, check their Gas Safe card shows the relevant categories (CCN1 for domestic boilers, CENWAT for central heating).

Every plumber working in your home should carry public liability insurance of at least £2 million. This covers accidental damage to your property — a flood from a poorly connected pipe, a cracked tile from dropped tools. Ask to see the certificate before work starts. Check the expiry date. If a plumber is employing others (even informal workers), employers liability insurance is legally required. Do not confuse insurance with a guarantee — insurance covers accidental damage; a workmanship guarantee covers the quality of the work itself. Both matter.

Get at least three written quotes for any significant job. The same brief must go to all contractors — describe the problem or required work precisely so you are comparing like-for-like. The cheapest quote rarely represents the best value; it usually means something is missing — cheaper materials, fewer hours assumed, no contingency for complications. The most expensive is not automatically the best. Look for: a clear scope of work (what is included and excluded), specified materials with brands mentioned, a realistic timeline, and a clear payment structure. Ask each plumber what they would do differently from the others if they have seen the same job — their answers reveal experience.

No written quote — a verbal agreement protects no one. Cash only with no invoice — a sign of unregistered operation or tax evasion. High upfront payments — more than 10% or the cost of materials upfront is unusual for standard plumbing work. Reluctance to show qualifications or insurance — a legitimate professional is proud to provide these. Unable or unwilling to give a start date — reliability is the number one complaint about plumbers. Reviews that are all five-star and suspiciously generic — legitimate businesses have a mix of four and five star reviews with specific detail. Doorstep cold callers offering to fix a problem they have "spotted" — a classic rogue trader approach.

In a plumbing emergency, you cannot run through the full vetting process. But you can do three things: check Gas Safe on the spot (ask to see the card — it takes 10 seconds), agree a total price before they start (not just a call-out fee), and ask for a written quote for any follow-up work before committing. Legitimate emergency plumbers expect these questions. Scam operators resist them. If a plumber arrives and immediately says the work is much more complex than expected and will cost significantly more than quoted, get a second opinion before proceeding.

Our plumbers are Gas Safe registered, fully insured, and experienced with NW London's housing stock. We follow up on quality and are your first call if something is not right. You get the benefit of a personal recommendation without needing to know someone who has already done this.