How to tell if you have a hidden leak
Look for signs such as damp patches, mould or stained walls. A water bill that rises with no change in use is another clue. The sound of running water when everything is off is a third.
If you have a meter, check it with all taps off. If the dial still moves, water is escaping somewhere. See our guide on how to read a water meter.
DIY leak location methods
Check visible pipes and the area under sinks. Look at the toilet cistern too. A few drops of food colouring in the cistern show a leak if colour appears in the bowl.
Walk outside and look for wet ground or a patch of very green grass. Because soil hides leaks, you may see only the surface signs. Turn off appliances one at a time to narrow the search.
What professional leak detection can find
A specialist can use listening devices to hear the sound of a leak in a pipe. They may use thermal imaging to spot heat changes. Some use gas to trace small leaks.
These tools help find the spot without digging up floors or walls. As a result, repairs can be targeted. Our guide to leak detection methods explains how each works.
Common types of hidden leaks
Common leaks include pipe joints, supply pipes under floors and heating pipes. Leaks can also come from tanks, baths and showers. Outside, the supply pipe between the street and the house may leak.
Some leaks are slow and small, while others run freely. Both can cause damage over time, since water seeps into walls and floors.
What to do while waiting for an engineer
Turn off the water at the stopcock if the leak is serious. Move belongings away from the damp area. Take photos and keep notes for your insurer.
Check your water meter again to see if the leak is on your side of the boundary. If you think the leak is on the water company’s pipe, ring them. You can also ask for a free quote on our site.
As soon as the leak is fixed, dry the area well. Damp walls and floors can grow mould, because moisture lingers. Open windows and use a dehumidifier if you have one, and ask a builder to check if the damage is large.
Related guides and local help
If you want to know more, read Leak Detection Methods: Acoustic, Thermal and Tracer Gas. You can also read What to Do When a Pipe Bursts: A Step-by-Step UK Guide and Leak Detection Cost Guide: What Changes the Price Most, because they cover closely related problems.
These guides help too: Preparing Your Home’s Plumbing for Winter: A UK Guide, Bath vs Shower: Water Use, Running Costs and Drain Impact, Gas Safety: What Every UK Homeowner Needs to Know Today, Hard Water and Your Plumbing: Effects, Costs and Solutions and Frozen Pipes: How to Prevent, Thaw and Cope After a Freeze. Each one explains a related topic in plain English.
Need help near you? Read our plumbing help page first, or see Leak Detection in Brighton and Leak Detection in Brinsworth. You can also see Plumbing Repairs in Driffield, since every service page has a free quote form. We pass each request to a local drainage engineer.
