Toilet running causes stains in bowl (C) Daniel FriedmanRunning Toilet Repair Guide - How to Diagnose & Repair a Toilet that Runs

  • TOILET RUNS CONTINUOUSLY - CONTENTS: Running toilet repair guide: how to diagnose and fix running toilets. How to diagnose and fix toilet noises. Why a running toilet can ruin a septic drainfield. Toilets that keep running - fill valve does not shut off the toilet tank fill valve?
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How to fix a running toilet: Here we explain how to diagnose and fix the cause of a running toilet. If you hear your toilet tank refilling when the toilet is not in use, or if there is always condensation on the toilet tank, you are wasting water and you may be ruining the septic drainfield. More subtle running toilet problems include periodic poor flush of the toilet too.

This article series discusses the cause, diagnosis, and repair of toilet problems (water closet problems) such as a toilet that does not flush well, clogged toilets, slow-filling toilets, running toilets, loose wobbly toilets, and odors at leaky toilets. Here we explain how to diagnose and repair problems with toilets, leaks, flushes, odors, noises, running and wasted water.

Green links show where you are. © Copyright 2017, All Rights Reserved.

Green links show where you are. © Copyright 2017, All Rights Reserved.

Toilet Runs Continuously - Diagnosis & Repair

Stained toilet bowl indicates a running toilet (C) Daniel Friedman

[Click to enlarge any image]

Is your toilet running? Better go catch it!

That5 was a joke when we were kids. But a running toilet wastes water and it can flood a septic drainfield leading to very costly septic repairs.

Our page top photo as well as the photograph below both show ugly staining in a toilet bowl - strong evidence that both of these toilets have been running, wasting water, and sometimes giving bad flush performance as well.

And if your building is connected to a private septic system, a running toilet can easily flood and damage the septic drainfield or soakaway bed, inviting a sewage backup into the building.

There are also more subtle but troublesome snafus that occur when a building toilet keeps running. For example in a freezing climate building sewer lines close to the building may not be below the frost line. Instead the sewer line depends on the fact that it slopes to the sewer or septic tank to remain empty and thus immune to freeze-up problems.

But a dripping faucet or a running toilet, by sending a slow trickle of wastewater into the drain system, can cause a drain to freeze and back-up during cold weather.

Readers should also see ALTERNATIVE & WATERLESS TOILETS for a discussion of camping toilets, chemical toilets, emergency-use toilets, waterless toilets, graywater systems, composting toilets, home health care toilets, incinerating toilets, outhouses, and latrines.

How to Detect & Diagnose the Cause of a Running Toilet

Condensation on toilet tank (C) Daniel Friedman

A plumbing leak that causes a toilet to run, the only clues might be noticing that the toilet fill valve is sometimes re-filling the tank even though no one has used the toilet, or one might hear water running in the building drains, or if the property is served by a private septic system, the system may experience flooding and backups.

See PLUMBING DRAIN NOISE DIAGNOSIS for tracing noises to individual toilets or plumbing drains.

Vertical float toilet fill valve (C) Daniel Friedman

Toilet flapper valve in use (C) Daniel Friedman
Toilet tank parts (C) DanieL Friedman

Taking off the toilet tank top: Some of these simple toilet diagnosis steps require that you look into the toilet flush tank on the back of the toilet.

Just lift the top off of the toilet tank and set it carefully aside on the floor where you won't break it or trip over it.

Toilet with tank lid on seat(C) Daniel Friedman

If you leave the tank top on the toilet seat (as we did for this photo) you're asking for trouble, and also, it's a bit in the way. 

Our sketch below shows the parts you'll see inside the toilet tank. You may want to refer back to this drawing while reading the details of each class if individual toilet problems listed above and how they are detected, diagnosed, and repaired.

Toilet tank parts (C) DanieL Friedman

Tank reservoir toilets like the toilet in the sketch and in our photo just above, have been in wide use in North America since the 1940's.

While there have been improvements in toilet tank fill valves, flush valves, floats, and water savings, the design has remained about the same.

[Click to enlarge any image]

A flush lever moves an arm to lift a flapper valve or tank ball to permit water to rush into the toilet bowl below, washing away waste into the sewer pipe.

At the end of the flush cycle, a float arm, or a float moving on a vertical stalk (newer valves) drops to open a valve permitting the toilet tank to refill with water.

When the toilet tank water level reaches the proper level, the float closes the toilet tank fill valve.

Here is our list of toilet trouble diagnosis and repair articles. You will see that some toilet problems are fixed easily and right at the toilet by a simple adjustment, while others may not be the toilet's fault at all, and may need more thoughtful diagnosis and repair.


Continue reading at TOILET TANK SWEATS - condensation may also indicate a running toilet, or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.


Or see TOILET TYPES, CONTROLS, PARTS - identify toilet parts & controls

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