If your latest Metro Vancouver utility bill made you do a double-take, you're not alone. A sudden 30–60% spike in water usage is one of the most common calls we get at Mr. Plunger — and the cause is almost always one of seven specific things. The good news: three of them you can identify and fix yourself in under an hour. The other four need a licensed plumber, and the longer you wait, the more they cost you.
Here's how to walk through it systematically, BC home by BC home.
The 7 causes, ranked by how often we find them
- Running toilet (the silent flapper leak) — accounts for ~30% of all spike calls
- Outdoor irrigation timer stuck open or a sprinkler head broken at ground level
- Hidden slab leak under a basement or main-floor concrete pour
- Pinhole leak in a copper supply line behind drywall
- Failing pressure-relief valve on the water heater dumping water continuously
- Service-line leak between the city meter and the house
- A wet-vented fixture (older Surrey or Vancouver homes) leaking inside the wall
How to diagnose it yourself in 15 minutes
Before you call anyone, do the meter test. It costs nothing and rules out 80% of the noise.
Step 1 — Find your water meter
In most Lower Mainland homes the meter is at the curb in a concrete box (lift the steel lid with a screwdriver), or inside near where the main supply line enters the house — often in a basement, crawlspace, or mechanical room. Take note of the digit display.
Step 2 — Shut off every fixture in the house
Turn off every tap. Don't run the dishwasher, washing machine, or ice maker. Don't flush a toilet. Check that your irrigation system isn't scheduled to fire. Then wait 30 minutes without using any water.
Step 3 — Re-read the meter
If the dial has moved, you have a leak somewhere in the system. The rate of movement tells you the rough size — a slow creep is a flapper or a pinhole; a fast spin is a service line, slab, or pressure-relief valve dump.
Causes you can fix yourself
Running toilet (flapper failure)
Add a few drops of food colouring to the tank, wait 15 minutes, then check the bowl. If the bowl has changed colour, your flapper is leaking. A replacement flapper from Home Depot or Rona costs $8–15 and takes 10 minutes to swap. Turn off the supply valve under the toilet, flush to drain the tank, unhook the chain, lift the old flapper off the flush valve pegs, install the new one, reconnect the chain so there's a tiny bit of slack when the flush handle is at rest, turn the water back on. Done.
Outdoor irrigation or sprinkler leak
Check the irrigation controller for stuck zones — a relay that fails on can run a zone 24/7 without anyone noticing. Walk the yard at dawn and look for soft, soggy patches over the irrigation lines. A broken sprinkler head at ground level can dump 5–15 gallons per minute when the system fires.
Wet utility-room or laundry connection
Check the inlet hoses on your washing machine, the under-sink supply lines on your kitchen and bathroom faucets, and the supply line to your toilet. A weeping connection at a compression fitting won't make a visible puddle but will quietly waste water for months.
Causes that need a licensed plumber
Slab leak
If a section of your basement or main-floor concrete is warmer than the surrounding floor, or you hear water running under it with no fixture on, you have a slab leak. These need acoustic and thermal leak detection to pinpoint, then either a spot repair (jackhammer in, replace section, patch concrete) or a re-route around the slab. Either way it's a plumber job.
Pinhole leak in a copper supply line
Older Lower Mainland homes (1960s–1990s) often have type-M copper supply lines that are now hitting end-of-life. Pinholes start tiny and weep. Symptoms: a damp patch on drywall, a faint hissing inside a wall, a chronic mineral stain on a ceiling. Acoustic locating finds the leak to the inch; a targeted drywall cut limits the damage; a fitting or section replacement closes the loop. Mr. Plunger's leak-detection service is built around this exact scenario — see /services/leak-detection.
Water heater pressure-relief valve (T&P) dumping
If your water heater is over 8 years old and you find a tray of water under or near the unit, the T&P valve may have started weeping. This is also a safety issue — the T&P is the failsafe against tank rupture. Replace the valve or the unit; don't ignore it.
Service-line leak between the meter and the house
The hardest to find. If your meter spins but you can't find water inside the house, the leak is underground between the meter and where the supply enters the building. Acoustic locating from the surface, pressure-decay testing on the line, then a targeted dig or trenchless replacement.
How much does each one cost to fix?
We don't post flat-rate book pricing — every quote is specific to what we find on site after diagnosis. But to give you order-of-magnitude context: a flapper swap is a hardware-store DIY ($10). A pinhole repair is a few hundred dollars in most homes. A slab leak repair or service-line replacement is the most expensive category. We give you an honest written estimate before any work starts, and we tell you straight whether a repair is worth it or whether replacement is the smarter spend.
Frequently asked
How fast can a leak run up the bill?
A continuously running toilet wastes 30–50 cubic metres a month in a Metro Vancouver home — that's roughly $50–80 on the water bill at current rates, on top of the wasted water itself. A pinhole on a hot-water line wastes water AND the natural gas or electricity to heat it.
Will my insurance cover the repair?
Most BC homeowner policies cover SUDDEN water damage (a burst pipe) but not the repair of the leak itself. They also typically don't cover damage from slow, ongoing leaks that you 'should have noticed'. We provide a detailed locator report and itemized invoice so you have documentation if you do file a claim.
How long does leak detection take?
Most residential leak-detection calls take 1–2 hours from arrival to a marked location. Slab leaks take longer because we need both acoustic and thermal locating. We bill at a transparent hourly diagnostic rate, quoted up front before we start.
Got the problem we just described? We answer 24/7 across Surrey, Langley, Vancouver, Burnaby, Coquitlam, Delta, White Rock, and Richmond. Call Mr. Plunger Plumbing & Drainage at (604) 870-1442 — real plumber on the line, exact ETA before dispatch, up-front quote before any work starts.