London External Moling & Hertfordshire Water Main Repairs

Call Flow XP today on 07929 433520 to get a free quote on all our London water repair services!

Water Mains Replacement London, Hertfordshire and Essex

Welcome to Flow External Plumbing, your water main replacement experts London!

Here at Flow External Plumbing we are specialists in water supply pipe repairs, water supply pipe replacement and lead pipe renewals within Greater London, Hertfordshire and Essex.

Our London based external moling and water main replacement specialists are highly skilled and our London based qualified engineers are committed to the highest level of customer care at all times.

Our aim is to offer a truely complete service, where everything we do is done with the client in mind. From when we start the job at a time that suits you to offering advice that might be of help, we will endeavor to keep the site as clean and safe as possible around the clock.

Be it a localised water main repair, water pipe replacement or water supply pipe replacement using the latest in moling technique (trenchless technology) we will provide you a cost effective alternative to traditional trenching methods, minimising the time, cost and disruption to your property. 

So whether you’re looking to replace your outdated water supply, have low water pressure or you have simply sprung a leak and would like to take advantage of our water pipe experts, please call us to take away the stress.

We offer a number of external plumbing services including London lead pipe replacement and underground moling.

(Moling is the installation of underground services with minimal digging required. All work we complete has a 15 year guarantee!)


Why Impact Moling in London?
Impact Moling is a cost effective and environmentally friendly solution for many underground installation projects. Instead of digging trenches to lay pipes/ducts and cables Flow External Plumbing use a technique called Moling, which, uses a smaller footprint with no need for deep excavations and operates through various ground types, but not all.

London Water Pipe Repairs & Replacements

Our water mains replacement starts from the stop tap at the boundary of your property up to the connection inside your house, giving you a single, seamless water supply replacement that has superior integrity and flexibility, leaving it less prone to splits and cracks with none of the risks of lead contamination.

External Moling & Trenchless Installations In London

Impact Moling is a technique in which a pneumatic piercing tool is used to create a bore hole. The ground is compacted and displaced rather than excavated and removed, therefore disruption and reinstatement are minimal.
Impact Moling is the simplest and least expensive trenchless technology installation method.

London Lead Mains Replacement & Lead Mains Installations

Save time and money on water main replacements with the latest trenchless techniques from Flow External Plumbing. Our state-of-the-art moling equipment can bore accurate, efficient channels for new pipe work without the need for large scale excavation.

London Drainage Repair & Drainage Services

When it comes to the designing and installation of drainage systems, we have plenty of experience working in both the private and public sectors. As well as adhering to all of the relevant health and safety regulations, our team works hard to ensure the whole process goes smoothly for our clients.

London Mains Laying & Mains Diversions

Flow External Plumbing can supply and install all types and sizes of water main. In addition to large scale mains laying services we also provide a bespoke design service for smaller projects, such as lead renewal, meter installations and diversions. So no job is too big or too small.

London Leaking Pipe Repair & Leak Detection

Leaking or burst pipes can form to create problems, which can turn into a disaster if not taken care of quickly. We offer our clients a priority service whenever they find themselves dealing with this kind of problem. If you are living in London, Essex, Surrey, Hertfordshire, or Kent, you can call us for pipe replacement work.

Water Mains Replacement London, Hertfordshire and Essex

What are some of the benefits of our services?

Restore High Water Pressure

With washing machines, power showers and central heating systems needing water…..

With washing machines, power showers and central heating systems needing water, old supplies (often Lead) do not provide an adequate flow due to a smaller bore size. This poor pressure can be increased through the installation of a greater internal diameter pipe of 25mm or greater to your property, resulting in increased pressure from your taps.

No Unsightly Ground Distruption

At Flow External Plumbing, as most of our excavations and requirements are of no…..


At Flow External Plumbing, as most of our excavations and requirements are of no more than 1 metre square and 1 metre deep to be able to receive the mole, there is no need to disturb the surface, the mole burrows discreetly under gardens, patios and driveways. With our moling technique, trenchless water pipe replacement proves to be far quicker, more efficient and certainly more cost-effective than traditional trenching methods, with no need for unsightly channels dug through your garden and driveway.

Expert Moling Team - 24/7

At Flow External Plumbing, our team have years of moling experience. This means you will always…..


At Flow External Plumbing, our team have years of moling experience. This means you will always get a professional service no matter which type of work you require from us. Be it a lead pipe repair / replacement or water supply pipe upgrade due to low water pressure.

Our moling technology allows us to solve any water supply problems without any hassle for you at a moments notice. Our trenchless water pipe replacement technology means that you get a fast solution that will not require us to lift any of your patio or driveway. 


Moling / Drilling Specialists

At Flow External Plumbing our moling technology enables us to solve your water supply problems with the…..


At Flow External Plumbing our moling technology enables us to solve your water supply problems with the minimum of fuss. We can often perform water pipe replacements without digging long trenches across your property. Flow External Plumbing’s water pipe replacement provides a fast and tidy alternative to cutting trenches or lifting driveways and patios – we simply dig small pits and use high-tech pneumatic moling units that effectively burrow their way between the excavations, passing under driveways, lawns and patios with no surface disruption whatsoever. Moling saves time, mess and money, offering a cost-effective water pipe replacement for both domestic and commercial applications.

Value For Money!

At Flow External Plumbing our philosophy is to keep things simple; we do the right job, at the right price…


At Flow External Plumbing our philosophy is to keep things simple; we do the right job, at the right price, at a time that’s right for our customer. We provide a guaranteed, reliable and efficient service together with outstanding customer care provided by polite, friendly and competent engineers.

We’re proud of our reputation for speed and efficiency, as well as our professional attitude and commitment to minimising any mess or disruption to your home or business. We’re happy to perform site inspections to discuss your installation options available to you before undertaking any repairs or new installs using traditional methods or specialist no dig technology.

Energy Savings

Improved water flow is beneficial and can save you money as improved delivery to water….


Improved water flow is beneficial and can save you money as improved delivery to water dependent appliances will help reduce energy costs. If you currently have a lead or steel supply and experience low water pressure making use of our lead pipe replacement service can increase your water flow by up to 60% and go towards that holiday.

Water Mains Replacement London, Hertfordshire and Essex

Onsite Case Study

Project: Hampstead Garden Suburb Conservation area

As with this job we aim to provide a professional and detailed approach to each individual project.

As this was a conservation area we needed multiple meetings with Thames water, The Hamstead Garden Suburb trust and the Hamstead Garden Suburb residents association and architects, providing detailed drawings, method statement and risk assessment.

The end result was the project being delivered on time and within budget.

Flow External Plumbing - PROPOSED-WATER-MAINS Technical Drawings London 1
Flow External Plumbing - PROPOSED-WATER-MAINS Technical Drawings London 1

Flow External Plumbing are Water Board approved (Water Safe), have an impeccable safety record and carry full public liability insurance.

Our workforce is fully trained, vastly experienced and used to working closely with our clients to achieve the highest levels of satisfaction. Our engineers will explain to the client the works that are going to be undertaken before work commences and will keep the client informed of any developments throughout the process until completion.

Regardless of which type of underground service you need installed, whether you are a domestic, commercial or industrial client, Flow External Plumbing have the training, ability and experience to complete it out efficiently, effectively and with minimal disruption to your property.



One of our surveyors will visit your property and take precise measurements. They will explain the process, go through final designs and make sure that you are 100% satisfied.



A job can be won or lost at the planning stage, we ensure the job is throughly planned out and all potential issues are resolved, parts are ordered and teams understand the job at hand.



Once the plans and timescales have been agreed we are all set to go ahead with the pre-arranged installation date. Our installation and engineering teams will arrive at the time agreed and get to work right away.



With the job complete, you can sit back and relax knowing,  if there are any issues down the line due to engineering faults we will repair or replace work in line with our terms and conditions.

Flow External Plumbing - Plumbing Man Repair Local London

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24 Hours a Day


Water Mains Replacement London, Hertfordshire and Essex

Client Testimonials

Barnet EN4

Dear Karl, May we take this opportunity to thank you for an excellent job, as you are aware the reason for the initial call was the stream of water pouring down our front driveway due to a broken stop-cock. After an initial phone call, you arrived the next day (at the agreed time) to assess the work. You explained that whilst replacing the broken stop-cock the fitting of a new water main to replace the original lead water main would be beneficial. You advised us of the cost at the time, which we thought was very reasonable and you said that you would phone us the following day to advise us when you were able to undertake the work. Within a week of the initial phone call the work was completed to a very high standard. Neighbours who saw the depth of the hole that you had to dig to get to the water main have commented that “you wouldn’t have known your drive had been dug up” as the block pavers were replaced to their original state (if not better)!

As we have a pressurised water system the increase in waster pressure due to the new water main is incredible.

For these reasons, we would definitely recommend ‘Flow External Plumbing’ to anyone that requires your services.

Mr & Mrs P James

Winchmore Hill N21

I am writing to thank you for completing the excellent job carried out on Thursday in replacing the lead service pipe. I was delighted that you were able to install the new inlet pipe by using the moling technology, thus avoiding excavating more of my driveway than the original inspection hole. I appreciate the time and extra trouble you and your colleague took in ensuring there was no damage inside my home as you connected the internal services.

Please use this letter as an introduction to other client sand rest assured that if i here of family or friends facing similar problems with deteriorating lead pipes i will recommend your firm.

Mr M Griffin

London N19

I needed to have the old lead water main replaced with a new plastic pipe at my property. A neighbour introduced me to flow. I found them to be incredibly efficient, from arriving on time to give us a quote.

On the day the work was to be carried out, they arrived promptly with a courtesy call to notify me of their arrival time. The work was carried out with the utmost efficiency. the finished job was of an excellent standard, and i was left with no mess at all. i would recommend this company to anyone considering any external plumbing.

Mr Boorman