How to Fix a Running Toilet

A running toilet is sunk water cost.


The average running toilet can waste up to two gallons of water per minute. Considering nearly 750 million people on earth lack access to a clean source of H2O, letting your on-tap, endless supply continuously pour down the drain seems pretty selfish. Not only that, its incessant hiss serves as a constant reminder to everyone in range that your DIY skills are seriously lacking. Lucky for you, we’re here to help. Most fixes can be accomplished in less time than it takes to, um, read the morning newspaper, and won’t require any tools at all, other than a belt (this isn’t an excuse to advertise your plumber’s crack).

1Diagnose the flow. First things first, we need to diagnose what’s causing the relentless flow. To do that properly, you need to understand the mechanics housed within your porcelain perch. Lift the lid off of the rear tank and you’ll notice that the flush lever is attached to a flap via a chain. When you flush, that flap lifts and the entire contents of your tank empty into the bowl below, displacing the water and waste down into the drain. When this happens, the float drops, thus opening the fill valve. Water now flows into the tank, refilling it via the refill tube. As water levels top off to their predetermined level, the float hits its high spot, closing the fill valve and stopping the water — at least in a perfect world. That means things could go wrong at any combination of one of five places: the flap, the chain, the float, the float arm or the fill valve.

2Check the flap. Most problems can be solved at the flap. The rubber flapper needs to fully close and seal the tank off from the bowl to ensure the water fills the tank and doesn’t run. The simplest solution is to make sure your toilet cleaning puck hasn’t shifted position (pro tip: if you use blue pucks, put on some dishwashing gloves first). If there are no obstructions, manually lift the flapper and watch how it lands. If it’s out of alignment, check that the pivot points on which it’s hinged aren’t becoming jammed. You may need to swap out the flapper itself or just give things a good cleaning. The rubber can degrade over time, so check it for cracks and brittle edges. The same rules apply for toilets equipped with a ball-style closure.

3Make sure the chain isn’t catching. If your flapper looks to be in good shape but still won’t seal properly, take a peek at the chain connected to it. It may be getting caught on something and preventing the flapper from closing fully. If the problem requires a chain replacement, this takes no time at all — just make sure you match lengths before the swap.

4Look to the float. One of the more common issues lies with the float. Since the float is what activates the water valve itself, it needs to operate smoothly to turn off the waterworks. Make sure it isn’t getting hung up on the filler tube or any other obstacles. If your float is the bulbous type mounted on an arm, check it for any holes. If you see one, it means water is sinking your float. Most floats can be spun freely on their axis to position the hole on top, but replacement or repair is the best route here.

5Adjust the arm. The float is connected to the valve via the arm. Some are wire and others are plastic, but all of them are adjustable. You’ll know yours needs an adjustment if it is functioning, but when the tank fills to the fill line, the water keeps flowing into the overflow tube. If your arm is wire, bending the arm down slightly will cause the float to close the valve sooner and stop the flow. If it’s plastic, there should be a thumb-screw of some sort midway to the float. You can adjust the arm angle using this pretty easily and stop flow from continuing. If your float is inline with the valve post, pinch the clip connecting it to the valve via the wire and lift the float until the valve shuts. Now let go of the clip and you should have successfully adjusted the closing position of your valve.

6Evaluate the valve. If your valve simply won’t close, first give it the once over for limescale build-up. A simple cleaning with a stiff bristled brush and some CLR (calcium, lime and rust) can go a long way here — especially if you’re not the first king to sit on this throne. If that still doesn’t enable the valve to close, you may be looking at swapping out internal washers and seals. For some units this may be more trouble than it’s worth. If you can’t easily access them, look into replacing the whole valve mechanism. This usually isn’t too daunting a task, even for a DIY newbie, provided you read and follow the manufacturer’s directions.

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