1. Verify Gas Safe registration for any gas work
By law, only Gas Safe registered engineers can work on gas appliances in Great Britain, so always ask. Ask to see the engineer’s ID card and check what work it covers. You can also check the register online.
If a plumber cannot show proof, do not let them work on gas. Unsafe work can cause leaks and carbon monoxide poisoning. Do not take the risk.
2. Check WaterSafe membership for water supply work
WaterSafe is a scheme that lists approved plumbers for work on water fittings, so it is worth a look. Check whether your plumber is a member. Ask them which schemes they belong to.
Membership is not the only sign of quality, yet it gives you extra confidence. Ask for details in writing, if you can.
3. Ask for three references and call them
Ask for the names of recent customers, because their stories show how the plumber works. Call them and ask how the job went. Did the plumber arrive on time, keep the site tidy and stick to the price?
Look at online reviews too, but read them with care. A mix of honest comments is a good sign, while a flood of similar five-star reviews may not be.
4. Get at least two quotes for non-emergency work
For planned jobs, compare quotes from at least two firms, since prices vary a lot. Make sure each covers the same work. A quote that is far below the rest may leave things out.
Ask each plumber to explain the price. Take your time, since rushing leads to mistakes.
5. Demand a written quote before work starts
A written quote should list the work, the parts and the total price. It should say what is not included. Keep it, because it protects both sides.
If the job changes, ask for the new price in writing. This avoids surprises on the final bill.
6. Check for public liability insurance
Ask whether the plumber has insurance in case of accidents. Ask to see proof. A professional will not mind the question.
Insurance matters because a mistake can cause expensive damage. Check the policy covers the type of work you need.
7. Avoid the ‘cash in hand’ offer
Be wary of anyone who wants cash with no paperwork, because you may have no proof of the work. You may have no record of the work, so it is hard to complain later. Always ask for an invoice and a receipt.
A trader who avoids paperwork may avoid responsibility too. Choose a plumber who gives clear documents.
8. Check that their vehicle and presentation matches the job
A professional usually has a clear business name and contact details. Check that the name matches the paperwork. This is only one sign, though, so do not rely on looks.
Look for a company address and a working phone number. Ask how long they have worked locally, but check the answer.
9. For drainage: check CCTV capabilities
For drain problems, ask whether the engineer can use a camera, since it shows the real fault. It shows what is wrong, so you pay for the right fix. Our CCTV drain survey page explains how it works.
Ask for the footage and report. A good engineer will explain what they find.
10. Trust your instincts — and don’t be pressured
If someone pushes you to agree on the spot, walk away, because good plumbers allow time. Good plumbers give you time to think. Be careful of those who claim a problem is urgent without proof.
Ask questions and take notes. If something feels wrong, get a second opinion.
Where to find reliable tradespeople
Ask friends and neighbours for names. Check trade scheme websites and your local council. You can also ask for a free quote on our site, and we will pass your details to a local plumber.
Related guides and local help
If you want to know more, read How to Read Your Water Meter and Use It to Spot Leaks. You can also read Hot Water Not Working: A Diagnosis Guide for UK Homes and Lead Pipes: Health Risks, How to Spot Them and Replacement, because they cover closely related problems.
These guides help too: Hard Water and Your Plumbing: Effects, Costs and Solutions, Low Water Pressure: Causes, Diagnosis and Fixes in the UK, Bath vs Shower: Water Use, Running Costs and Drain Impact, New Bathroom or En-Suite: A Complete Drainage Planning Guide and Leak Detection Cost Guide: What Changes the Price Most. Each one explains a related topic in plain English.
Need help near you? Read our plumbing help page first, or see Plumbing Repairs in Burton Joyce and Plumbing Repairs in Burwash. You can also see Leak Detection in Ealing, since every service page has a free quote form. We pass each request to a local drainage engineer.
