What you are actually being sent to
Thames Water publish a short address for approved plumbers, and their leakage code of practice points customers at it when a leak is found on a private supply pipe. Follow it and you arrive at Thames Water's find a plumber page. That page does not list companies. It gives two routes and a disclaimer.
For work inside the home, it says: "If you're working on plumbing inside your home, we recommend choosing a WaterSafe approved plumber. This will ensure the work meets high standards and protects the quality of drinking water in your home."
For work outside, it says that if you are working on the underground pipe supplying your property up to the internal stop valve, you may want specialist groundwork contractors, who can also be used for leak detection and for laying new pipes by moling, and it recommends "choosing a WaterSafe approved contractor. They're recognised by water company schemes APLUS, WaterMark and WIAPS to carry out specific types of work."
So there is a list, it is just not Thames Water's. It is the WaterSafe register, and what approval means there is a more useful thing to understand than the brand on the page.
The half of the page most people skip
Underneath the two recommendations sits a disclaimer, and it is the most informative block on the page. In Thames Water's words:
- "Your contract will be with the approved plumber / underground worker and not Thames Water. We can't give assurance of their availability or guarantee their work."
- "We won't get involved in any contractual disputes between you and the plumber or underground worker."
- They recommend obtaining at least one quote before employing any contractor, and asking in advance whether there is a charge for giving a quote.
- "Please ensure you receive a certificate of water regulations compliance from the plumber or underground worker, after they have completed the work."
- "Please ensure that the work is carried out or witnessed by one of the named persons listed as being approved for that company."
- Approved companies and persons "are not able to carry out any work in the public highway without consent from the local Highway Authority."
Read together, that is Thames Water saying: we are telling you where competent people are registered, we are not vouching for any of them, and we will not referee. Which is reasonable, and it is worth knowing before you treat the word "approved" as an endorsement.
Approval attaches to people, not logos
The line about named persons is the one that catches homeowners out. A company appears on the register because specific individuals within it hold the qualification. If the firm sends someone else, the job is not covered by the approval, and the Certificate of Compliance that gives you the statutory defence under section 73(1A) of the Water Industry Act 1991 may not be available.
The fix takes one question on the phone: who is the approved person and will they be doing or witnessing the work?
Why Thames Water cares who you use
It is not politeness. Once a leak on your side of the boundary is confirmed, you have four weeks to fix it, and on their leaks page Thames Water reserve a right: "If you didn't use a WaterSafe approved plumber, we may come out to check their work. We'll carry out and charge you for extra repairs if we think they're needed."
That is a real risk attached to a cheap repair. If the repair is done badly and the leak is still running when they check, you are paying twice and the Section 75 process is still open. Using a plumber from the register does not make your work immune from inspection, but it removes the stated trigger for one.
Does Thames Water send its own plumbers?
People search for "Thames Water plumbers" expecting a phone number that sends a van. For pipework on your side of the boundary, that is not how it works. Thames Water are responsible for the main in the street and the communication pipe up to the boundary, usually the outside stop valve. From there to your house, and everything inside, is yours, and they point you to the register rather than sending someone.
So the first question is which side of that line the water is on:
- Water in the road or pavement, or at the outside stop valve chamber: report it to Thames Water. It is their repair and you should not be paying anyone for it.
- A wet patch in the front garden or drive, a meter still turning with every tap off, or a letter saying the leak is on your supply pipe: that is private pipework, and you need your own plumber or leak specialist. The four-week repair clock runs from the letter.
- Water inside the house: private pipework, full stop. Turn the stopcock off first. If you cannot find it, this is where to look.
The only exception is the discretionary help described further down this page for customers in vulnerable circumstances or where there is a risk to life or the network.
Searching the register for your area
The WaterSafe register searches by postcode, and that is the way to use it. Searching by borough or county gives you a longer, less relevant list. A firm that covers your postcode, lists external or underground work if that is your job, and can name the approved person who will attend is the shortlist.
If you are outside central London, check the name on your water bill before you read any further on this page. Thames Water's supply area is not the same as the M25, and a different water company may supply you even where Thames Water handles the sewerage. Our page on what Thames Water approved contractor status covers goes into that, and into what the approval does and does not exempt.
Becoming approved, if you are a plumber reading this
Thames Water's page says plumbers and groundworkers in their region can join the Water Industry Approved Plumber Scheme, WIAPS. WaterSafe describe WIAPS as managed by Water Regs UK Ltd on behalf of the majority of water companies in England and Wales, and as operating everywhere in England and Wales except the area covered by Anglian Water. The other routes onto the WaterSafe register are APHC, CIPHE and, in Scotland and Northern Ireland, SNIPEF.
What Thames Water will and will not do at your property
Their household customer side leakage code of practice sets the limits of their own involvement. They will help fix a supply pipe leak at their discretion for customers in Priority Services Register categories or on their WaterHelp or WaterSure schemes, and where there is a risk to life or to the supply network. Where they do repair, they say they will "repair your supply pipe up to where it enters your building, but we won't fix pipework underneath a building" — so in a converted flat, to the point the pipe enters the main building, not to your door.
They also say that where they cannot avoid digging on a footpath or driveway they will restore the surface to make it safe, but cannot do specialist work such as relaying block or crazy paving, and that if you arrange that yourself you carry the cost. That is the reinstatement gap this trade leaves behind, and it is the reason we do that part ourselves.
Choosing, without the badge doing the thinking
Three questions get you further than any list:
- Which scheme are you on, and who is the named approved person? Then check the WaterSafe register yourself. Free, and it takes a minute.
- How will you find the leak before you dig? On a supply pipe under a London front garden there is usually one right place to excavate and several expensive wrong ones. Acoustic correlation, tracer gas on a drained line and thermal imaging exist so the hole goes in the right place.
- Who puts the surface back? Get the answer before the work, in writing. A tiled Victorian path or a resin drive is not restored by a shovel of sand and an apology.
Our own answer: our work is charged at £150 per hour, agreed before we attend, and if we do not find the leak you do not pay for the time we spent looking. We repair the pipe and we put the floor, path or ceiling back. Pricing is one page and it does not move.
When not to call us
If the water is coming up in the road or the pavement rather than inside your boundary, that is Thames Water's communication pipe or main and you should report it to them, not pay anybody. If you rent, the repair is your landlord's responsibility, and the useful thing you can do is tell them in writing and keep a copy. And if all you need is a compliance certificate for a fitting somebody else installed, no plumber can certify work they did not do.
