Why Is My Toilet Constantly Running? (Easy Fixes)

A Running Toilet Wastes Serious Water

That constant trickling sound isn't just annoying — a running toilet can waste 200+ gallons per day. That's $50+ per month in Vancouver water rates.

The good news: most running toilets are easy to fix yourself.

How a Toilet Tank Works (30-Second Primer)

When you flush:

1. Flapper lifts, water drains into bowl
2. Bowl empties, flapper closes
3. Fill valve refills the tank
4. Float rises with water level
5. Float tells fill valve to stop

A running toilet means something in this system isn't working right.

Cause #1: Bad Flapper (Most Common)

The flapper is the rubber seal at the bottom of the tank. When it wears out or gets dirty, water leaks past it into the bowl — triggering the fill valve to keep running.

How to test:

1. Remove tank lid
2. Add a few drops of food coloring to the tank water
3. Wait 15 minutes without flushing
4. If color appears in the bowl, your flapper is leaking

How to fix:

1. Turn off water — shut-off valve is behind the toilet
2. Flush to drain the tank
3. Remove old flapper — usually just unhooks from the overflow tube
4. Take it to the hardware store — get a matching replacement ($5-10)
5. Install new flapper — hooks on the same way
6. Turn water back on and test

Time: 15 minutes | Cost: $5-10

Cause #2: Float Set Too High

If the water level is set too high, water constantly trickles into the overflow tube — which drains into the bowl, triggering the fill valve.

How to test:

1. Remove tank lid
2. Watch where the water level is relative to the overflow tube
3. If water is flowing into the tube, the float is set too high

How to fix:

Ball float (older toilets): Bend the float arm downward slightly to lower the water level.

Float cup (newer toilets): There's an adjustment screw or clip on the fill valve. Turn/slide it to lower the float position.

The goal: Water should stop about 1 inch below the top of the overflow tube.

Time: 2 minutes | Cost: Free

Cause #3: Faulty Fill Valve

If the flapper is fine and the float is set correctly, the fill valve itself may be failing.

Signs of a bad fill valve:

• Water keeps running no matter what you adjust
• Valve makes humming or whining sounds
• Valve doesn't shut off completely

How to fix:

Replacing a fill valve is a little more involved but still DIY-friendly:

1. Turn off water and flush to empty tank
2. Disconnect water supply line
3. Unscrew the old fill valve and remove it
4. Install new fill valve (follow package instructions)
5. Reconnect water supply
6. Adjust float to proper level

Time: 30 minutes | Cost: $15-25

Quick Diagnostic Flowchart

Toilet runs constantly → check flapper ↓ (flapper is fine) Check water level → is it flowing into overflow tube? ↓ (yes) → adjust float lower ↓ (no) Fill valve isn't shutting off → replace fill valve

Prevention Tips

Clean the flapper every few months — hard water buildup can prevent a good seal

Don't use drop-in tank tablets — the chemicals degrade rubber parts faster

Replace flappers every 4-5 years — even before they fail visibly

When to Call a Plumber

Call if:

• You've replaced parts and it still runs
• The toilet is cracked
• You're not comfortable with DIY repairs
• You want it done right the first time

A professional can have your toilet fixed in 15 minutes with guaranteed results.