A toilet that won't stop running is the single most expensive 'small' plumbing problem a homeowner can ignore. A continuously running flapper wastes 30–50 cubic metres of water a month — that's $50–80 on the Metro Vancouver utility bill on top of the wasted resource itself. The fix is usually $10–30 in parts and 15 minutes of work. Here's how to identify which part has failed and the budget call between repairing your existing toilet or replacing it.
How a toilet tank actually works
Inside the tank there are three working parts:
- Fill valve (the tall vertical column on the left) — refills the tank after a flush, then shuts off when the float reaches its set height
- Flush valve and flapper (the round opening at the bottom of the tank) — releases the tank's water into the bowl when you press the handle
- Flush handle and chain — physically lifts the flapper to start the flush
If any of those three parts fail, you get one of the four symptoms below.
Symptom 1 — The bowl quietly trickles, water comes back on every few minutes
This is a leaking flapper. The flapper has either degraded (rubber stiffens over 5–8 years), warped, or has mineral build-up preventing a clean seal. The tank's water slowly drains into the bowl through the flush valve, the fill valve detects the drop, and refills — over and over.
How to confirm
Add 5–10 drops of food colouring to the tank water. Don't flush. Wait 15 minutes. If colour appears in the bowl, the flapper is leaking. Fix: a $8–15 flapper from Home Depot, Rona, or any plumbing-supply store.
How to replace
- Turn off the shut-off valve under the toilet (clockwise)
- Flush to drain most of the tank
- Disconnect the chain from the flush handle arm
- Lift the old flapper off the two pegs on the flush-valve assembly
- Slide the new flapper down onto the same pegs
- Reconnect the chain with just a tiny bit of slack when the handle is at rest (too much slack and the flapper doesn't lift fully; too little and it doesn't seal)
- Turn the water back on, let the tank fill, test-flush
Symptom 2 — The fill valve hisses or runs continuously
If the fill valve never shuts off, either the float is set wrong or the fill valve itself has failed. Look at the top of the fill valve — there should be a float arm or a cup-style float on the side. If the float is touching the top of the tank, or the water level is at or above the overflow tube, the float needs adjustment OR the valve has failed internally.
How to confirm
Lift the float arm or cup manually. If the water shuts off, the float adjustment is the problem — adjust the float clip lower so the water shuts off about 1 inch below the top of the overflow tube. If the water keeps running when you lift the float, the fill valve itself has failed — replace it with a Fluidmaster 400A or similar ($15–25, universal fit).
Symptom 3 — Ghost flushing (toilet refills randomly without anyone using it)
Same root cause as symptom 1, but the leak is slower. The flapper is dripping just enough to lower the tank's water level over an hour or two, triggering the fill valve to refill. Treatment: replace the flapper.
Symptom 4 — Water spilling into the overflow tube
If you see water flowing into the central tube in the middle of the tank, the water level is set too high. Either the float has migrated upward or the fill valve isn't shutting off. Adjust the float down by an inch and watch what happens.
When to repair vs replace the whole toilet
If your toilet is under 10 years old and the issue is one of the four above, repair every time. The parts are universal and cheap. If your toilet is 20+ years old and has had multiple repairs already, replacement starts to make economic sense — modern WaterSense toilets use 4.8L per flush versus the 13L of pre-1995 toilets, and the water savings pay back the replacement cost in about three years for a typical Lower Mainland household.
Other reasons to replace rather than repair:
- Cracked porcelain in the tank or bowl — unrepairable, will eventually leak or shatter
- Wobbling at the base on a tile floor — wax ring or flange is failing, often more cost-effective to swap unit and re-set
- Multiple component failures in one year — flapper, fill valve, and supply line all going
- You're doing a bathroom renovation anyway — install upgrades made cheap by the disruption already happening
Frequently asked
How do I know which flapper to buy?
Take a photo of the inside of your tank and bring it to the hardware store. The clerk can match the flush valve diameter (usually 2-inch or 3-inch) and recommend the universal flapper that fits. Most modern flappers are adjustable to compensate for slight differences in valve size.
Can I install a new toilet myself?
Many homeowners do. The wax ring and flange alignment are the parts that catch people out — if either is wrong, the toilet leaks at the floor and you end up with a soft subfloor over time. If you're doing it yourself, watch a couple of YouTube installs first, and don't rush the wax ring seating.
Same-day toilet installation?
Yes. We carry common standard toilets on the truck and can install same-day in most Lower Mainland addresses. Higher-end or unusual fixtures (skirted, wall-hung, smart toilets) we'll source and book the next day.
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.