Six signs of a hidden water leak in your home

Turn off everything in the house that uses water: taps, dishwasher, washing machine and the ice maker in the fridge. Write down the meter reading, then leave it alone for an hour, or overnight if you can manage it.

If the reading has moved and nobody has used water, something is leaking. A few drops an hour will not show up in a couple of minutes, which is why the wait is the part that matters.

To narrow it down, close the internal stop tap and run the test again. If the meter still moves, the leak is on the supply pipe outside the house rather than in it.

A stale, earthy smell in a room, a wardrobe or a cupboard is mould growing on plaster, timber or carpet underlay that has been damp for weeks. What you can smell is the mould rather than the water.

The point is not that it smells the day after a shower. It is that the smell is still there week after week.

Paint and wallpaper let go when the surface behind them takes on water. It shows up as a yellowing ring, a slight bulge, or a skirting board that has started to pull away.

On a wall with no reason to be wet, the water is coming from inside it.

Walk barefoot and you can sometimes feel one area noticeably warmer than the rest. On tiles or laminate that usually means hot water escaping below the surface, either from a hot water pipe or an underfloor heating loop.

A cold patch can mean the same thing on the cold side of the system, though it is easier to walk past without noticing.

If your usage has risen and nothing in the household has changed, take it seriously. Nobody has moved in and nobody is showering more, yet more water is going through the meter.

The catch is that the bill arrives after the fact. By the time the number reaches you, the leak has had a whole billing period to run.

A faint hiss or trickle inside a wall is easiest to hear at night when the house is quiet, and easy to dismiss as a radiator or the neighbours.

If the house is silent and you can still hear water, something is moving it. Rule out the obvious first, a cistern refilling or a water softener regenerating, and if none of those explain it, the sound is worth chasing.