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How to Check a Toilet for Leaks

A leaking toilet is not something you want in your home. Not only will your water bill skyrocket, but all that wasted water could cause structural problems in your floor, and the walls underneath. Water damage can be catastrophic, potentially leading to expensive mould remediation.

While a toilet leaking water is often silent and easy to ignore, all that water running down the drain adds up quickly! The average leaky toilet can waste about 757 litres of water per day. Not only will you have to pay for that on your water bill, but the charge may be doubled to cover the sewer fee as well. Add in the cost to the environment, and now that leaking toilet is more difficult to ignore.

If you suspect that your toilet may be leaking, it should be checked immediately. Not sure where to start? Here’s how to check a toilet for leaks:

  • Check your water bill. If it is higher than usual and you have not been using extra water by watering the lawn or have a home full of houseguests, something is probably amiss. Your water bill is one of the easiest ways to establish that something is causing additional water consumption. Recently, a Canadian snowbird received a water bill of more than $5,000 when her toilet began leaking while she was away for the winter! Yikes.
  • Open up your toilet tank and drop in some food colouring or a dye tablet. Wait about 15 or 20 minutes, and then check the toilet bowl. If the water in the bowl is tinted or coloured by the food colouring, this is a sign of a leak. The water from your tank should not enter the bowl unless you have flushed the toilet. This is the type of leak that is best dealt with by a licensed plumber, unless you’re very handy.
  • Inside the toilet tank, if the water level is above the overflow pipe inside, there may be an issue with your fill valve, sending a lot of water down the drain. This is probably not an issue you can or should fix on your own.
  • If you hear the water running when the toilet is not used, your toilet is leaking. Try jiggling the toilet’s handle. If this makes the running sound stop, the issue might be a simple one. Adjust the toilet’s flapper valve or the chain that connects the flush handle to the flapper valve. Many a toilet has been temporarily fixed with a wire twist tie in a pinch.
  • Examine your toilet bowl. If water is running down the inside without flushing, your toilet is probably leaking. This is another form of leak best handled by a pro.

If none of these tests identify a problem, but you still think that your toilet is leaking, try this: Shut off the water to the toilet (there should be a knob attached to the water intake pipe) before going to sleep. In the morning, check the toilet tank. If the volume of water inside the tank has dropped significantly, one of the components inside the tank is surely causing it to leak.

If one of those faulty components is causing the water to leak at the base onto the floor rather than into the bowl, you may be facing a much bigger problem than a high water bill. Leaking water can cause serious damage to your floor, and everything beneath and beside it, so the sooner you resolve it, the better.

Water leaking onto the floor at the base of the toilet may be caused by a failed seal, a faulty shutoff valve, or a loose supply tube. If it is leaking from the base, it is probably coming from the toilet bowl and is unsanitary. With each flush it will continue to leak, emptying dirty water onto your floor. This water will inevitably make its way into your flooring, subfloor, wall and even the ceiling of the room below. That leaking water will eventually cause structural damage, mould growth, and could potentially interfere with wiring inside the wall.

If this is the type of leak you are experiencing, this is the time to call in a professional for help. A licensed plumber will quickly determine the problem and repair it before further issues can arise.

If you suspect that your toilet may be leaking, try these tests as soon as possible. Whatever type of toilet leak you are experiencing, you’ll want to get it fixed right away, to avoid wasting water, and proactively avoid damage to your home and expensive utility bills. Some types of leaks are easy to fix, while others are best left in the capable hands of a pro who can be trusted to deliver an efficient, lasting solution, the first time around!

Your local leaky toilet experts, The Super Plumber is happy to be of service, specializing in the full scope of plumbing services for your home or business. Reach out to us today!