Water Leak Detection: How to Spot a Hidden Leak Early

Published 2026-06-02 · Rotorua Plumbers

Signs you have a hidden leak

Most hidden leaks announce themselves long before a pipe gives way. Watch for:

• A water bill that's crept up with no change in how you use water
• Damp patches, staining or bubbling paint on walls, ceilings or floors
• A musty smell or mould in a cupboard, under a vanity or in a wall cavity
• The sound of running water when every tap is off
• Warm spots on the floor (a leak on a hot water line) or unusually lush patches of lawn over a buried pipe

The meter test — do it yourself

Your water meter is the simplest leak detector you own. Turn off every tap and water-using appliance, then check the meter. If the dial or digits are still moving with everything off, water is escaping somewhere. For a clean check, note the reading last thing at night and again before anyone uses water in the morning — any change points to a leak you can't see.

Where leaks hide in Rotorua homes

Leaks love places you can't easily inspect: under concrete slabs, inside wall cavities behind showers, at corroded fittings on the hot water cylinder, in buried supply lines across the section, and at toilet cistern seals. In Rotorua, geothermal hydrogen sulphide can corrode copper and fittings faster than usual, so older homes here are especially worth keeping an eye on.

Why early detection saves money — and how we find it

The leak itself is rarely the expensive part — the damage it causes is. Months of moisture can mean rotten framing, ruined flooring and mould remediation that dwarfs the plumbing repair. A plumber locates leaks without tearing the house apart, using acoustic listening gear, pressure testing and moisture meters to pinpoint the source, then repairs just that section. If your bill has jumped or the meter won't sit still, get it looked at — see our repair and emergency plumbing service.

How we can help

• Leak repairs & 24/7 emergency plumbing
• Hot water & cylinder leaks