How to Fix a Running Toilet (and Stop Paying for Wasted Water)

A toilet that runs constantly, or that needs the handle jiggled to stop, isn't just annoying -- it can waste a surprising amount of water and add real dollars to your water bill every month. The good news is that the most common causes are inexpensive, low-risk repairs that most people can handle themselves with basic tools and a bit of patience.

Signs of a running toilet

• Water keeps trickling after the tank has already refilled
• The toilet "runs" briefly on its own every few minutes even when no one has used it
• You have to jiggle the handle to get the water to stop
• Water is audibly flowing into the overflow tube in the tank

What's usually causing it

Nearly all running toilets come down to one of a handful of parts: a worn rubber flapper that no longer seals, a chain that's too tight or too loose, a float set too high so the tank overfills into the overflow tube, or a fill valve that's simply worn out. None of these are expensive parts -- most cost less than a takeout coffee.

How to fix it yourself

• Turn off the water at the shutoff valve behind or beside the toilet before doing anything inside the tank
• Take the tank lid off and flush, watching where the water is escaping -- past the flapper, or into the overflow tube
• Check the chain connecting the flush handle to the flapper; it should have a small amount of slack when the flapper is closed, not be pulled taut
• Look closely at the flapper itself -- if it's stiff, warped, cracked, or coated in mineral buildup, replace it. This is inexpensive and doesn't require any special tools beyond your hands
• If water is running into the overflow tube, the float needs to be lowered slightly so the tank shuts off before it reaches that level
• If adjusting the float doesn't solve it, the fill valve itself may need replacing -- these come with instructions and a rubber washer, and the job typically takes 20 to 30 minutes

A neat trick for confirming a flapper leak: add a few drops of food colouring to the tank water and wait 15 minutes without flushing. If colour shows up in the bowl, the flapper is letting water through.

This repair involves kneeling or crouching beside the toilet for a stretch. If getting down to that level and back up is difficult, it's worth asking someone to help you get positioned, or simply calling a plumber -- this is a quick, inexpensive service call for most plumbers, and not something to strain yourself over.

Mistakes to avoid

• Replacing parts before you've actually watched where the water is escaping
• Overtightening the plastic nuts under the tank, which can crack them
• Using in-tank chemical cleaning tablets -- they can break down rubber seals faster and cause the very leaks you're trying to prevent

When to call a plumber

Call a professional if the shutoff valve itself is leaking or won't turn, if the tank has a visible crack, if the toilet rocks when you sit down (a sign it isn't sealed properly to the floor), or if you see water pooling around the base. Those situations point to something beyond a simple parts swap.