Signs of a Hidden Water Leak
Hidden leaks show up as rising bills, stains, smells and a meter that moves when nothing is on.
- Step-by-step, written from real jobs
- Tools to have ready and safe stopping points
- Where to stop and hand it to a licensed plumber
- Licensed plumbing trade
- Camera before digging
- Written job notes
- Phone-only booking
Summary card
Hidden leaks show up as rising bills, stains, smells and a meter that moves when nothing is on.
Under-sink cabinets with warped floors, grout that darkens around a tub, and a toilet that rocks are small clues worth following.
Leaks behind walls and under floors can run for months before they show. A rising water bill is often the first sign.
Moisture meters and thermal cameras help locate leaks without opening walls.
The procedure
- Note the meter dial, use no water for two hours, then compare
- Put food dye in the toilet tank and watch the bowl
- Look for bubbling paint or soft drywall
- Notice musty smells in cabinets
- Feel for warm floor spots
Tools to have at hand
- Water meter
- Flashlight
- Food colouring
Do it in this order
- 01
Turn off all water and watch the meter for movement
- 02
Look for stains on ceilings and walls
- 03
Check for warm spots on floors
- 04
Test toilets with food colouring
- 05
Listen for running water
The water meter is the easiest way to confirm a hidden leak.
Whitby Plumbing, from the job
Stop and phone a plumber if
- Meter moves with everything off
- Stains keep spreading
- You smell mould
Notes for Whitby
Region of Durham water bills can help you spot sudden jumps in use.
When the desk should take over
Phone us if that dial creeps while every tap is closed.