How do I fix a constantly running toilet in a Calgary home with hard water buildup?

A constantly running toilet in Calgary is almost always caused by one of three things: a worn flapper valve, a faulty fill valve, or a float set too high — and Calgary's hard water accelerates all three failure modes significantly.

The good news is that diagnosing and fixing a running toilet is one of the few plumbing tasks homeowners can confidently handle themselves, and the parts cost $15–$60 at any Calgary hardware store. The bad news is that Calgary's mineral-rich water from the Bow and Elbow rivers deposits calcium and magnesium scale on every internal toilet component, shortening the lifespan of flappers and fill valves from the typical 5–7 years down to 3–4 years in many Calgary homes.

Start by diagnosing which component is failing. Remove the tank lid and observe what's happening. If water is trickling into the bowl continuously, the flapper isn't sealing — either it's warped, encrusted with mineral deposits, or the seat it rests on is scaled and pitted. If water is running out through the overflow tube (the tall vertical tube in the centre of the tank), your float is set too high or the fill valve is faulty. Drop a few drops of food colouring into the tank — if colour appears in the bowl within 10–15 minutes without flushing, your flapper is leaking.

The flapper is the most common culprit in Calgary homes. Turn off the water supply at the shut-off valve behind the toilet, flush to empty the tank, then unhook the old flapper from the overflow tube ears and disconnect the chain from the flush handle arm. Before installing the new one, run your finger around the flapper seat (the ring the flapper rests on). If you feel rough, gritty mineral deposits, clean the seat with white vinegar and a scrubbing pad — a new flapper won't seal properly against a scaled seat. Universal flappers ($8–$15) work for most toilets, but if you have a Kohler, American Standard, or Toto toilet, a brand-matched flapper seals more reliably.

If the flapper checks out, inspect the fill valve. Calgary's hard water deposits scale inside fill valve mechanisms, causing them to stick open or fail to shut off completely. You can attempt to clean a fill valve by turning off the water, holding a cup over the top of the valve, turning the water back on briefly to flush debris out, then turning it off again — but honestly, fill valves cost $15–$30 and replacement is straightforward. Fluidmaster 400A or Korky fill valves are widely available at Home Depot and Rona locations across Calgary and are reliable performers in hard water conditions.

Adjust the float if water is running into the overflow tube. On modern fill valves, the float is adjusted by turning a screw or sliding a clip on the fill valve shaft. The water level should sit about 1 inch (2.5 cm) below the top of the overflow tube. If you have an older ballcock-style fill valve with a ball float on an arm, bend the arm slightly downward or adjust the adjustment screw to lower the water level.

A practical Calgary-specific tip: add a toilet tank cleaning tablet designed for hard water (look for ones containing citric acid rather than bleach — bleach tablets actually accelerate flapper degradation) to slow mineral buildup on internal components. Alternatively, pour a cup of white vinegar into the tank monthly. If you're investing in a bathroom renovation and replacing your toilet anyway, comfort-height dual-flush models (Toto, Kohler) are popular in Calgary for their water efficiency — especially relevant given Alberta's water conservation priorities.

When to call a plumber: If you've replaced the flapper and fill valve and the toilet still runs, or if you notice water on the floor around the base of the toilet (which suggests a wax ring failure rather than a tank issue), it's time to bring in a licensed plumber. Calgary plumbers typically charge $95–$150 per hour, and a toilet repair beyond basic component replacement usually takes under an hour. If you're planning a broader bathroom refresh, this is a good opportunity to get a contractor assessment of your full bathroom — Calgary Bath Remodeling can match you with a local bathroom renovation contractor for a free estimate through the Calgary Construction Network at calgaryconstructionnetwork.com.