Low Water Pressure in the Whole House? Check the Supply

The kitchen cold tap is fed straight from the mains, so it is the honest measure of the pressure arriving at your house. If that pressure has dropped over weeks or months, either the water company has changed something on its side, which affects the whole street, or your own supply pipe is losing water on the way in. A leak on a buried pipe acts like an extra tap that is always open, and the pressure at the real taps drops accordingly. Because the water soaks into the ground, there is often nothing to see at the surface.

Around Watford, Croxley Green, Rickmansworth and out into the villages, many houses still have their original supply pipe, in lead, galvanised steel or early plastic, running under the front garden and a concrete path. Ground movement, tree roots and simple age crack them. In London terraces the pipe often enters under the front bay and runs through the sub-floor, where a joint can leak for years. Older houses may also have a shared supply pipe with a neighbour, so a leak on their side lowers your pressure too.

We measure the pressure and flow at the stop tap and at the kitchen tap, then confirm at the meter whether water is escaping with everything off. From there we trace the pipe route across the garden and listen along it with the acoustic ground microphone; where the pipe is plastic or deep we put hydrogen tracer gas into it and detect where it surfaces. The spot is marked, dug by hand and the pipe repaired or a section replaced, all photographed for the report.

Water companies often provide a leak allowance or, in some areas, a one-off subsidised repair for supply pipes. If the leaking water has damaged the house, for instance undermining a floor, buildings insurance trace and access cover may apply. We will tell you honestly which route makes sense once we have found the leak.