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  • Writer's pictureJohn@LiteHouse

How We Inspect Toilets

Toilets are complicated devices that can fail in many ways. This article describes typical toilet malfunctions, provides information for diagnosing such malfunctions, and provides an overview of toilet design and functionality.

Trivia on Toilets:

  • "Sit toilets", while popular in Western countries, are not as common as the "squat toilets" found in most of the world.

  • The film "Psycho" (1960) was the first American film to feature a flush toilet. The scene, which many considered indecent, led to an outpouring of complaints.

  • The average person visits the toilet 2,500 times a year, approximately six to eight times a day. You spend about three years of your life on the toilet.

  • Most drugs are excreted in the urine, which enters the drain and eventually contaminates the fish. A recent EPA study found that fish contain trace amounts of cholesterol-lowering drugs, estrogen, antibiotics, caffeine and antidepressants.

How does the toilet work?

When a standard residential toilet, called a gravity toilet, is ready for use, both the tank and the bowl contain water. When the lever is pressed, it raises a rubber plug called a flapper, which allows the water in the tank to flow into the bowl. Water enters the bowl through small holes around the inside top of the bowl and through the siphon jet hole at the bottom of the bowl. Gravity forces the water and waste of the bowl into the waste pipe. The water flowing into the bowl also cleans the bowl. The water in the bowl is topped up with water supplied from the tank through the filling tube.


Inspectors should check for the following defects and perform the following tests:

  • cracks. Cracks anywhere on the toilet cistern or bowl (as well as any other fixture) should be recorded as defects.

  • flush all the toilets in the house. Unlike windows, of which the inspector is required to test only a representative number, every toilet should be tested. Specifically, inspectors should ask themselves the following questions when operating restrooms:

  • Is the toilet running continuously? Toilets that run continuously will waste a lot of water. If there is public water to the house, wasting water will increase your water bill. However, if the house is on a well, a continuously running toilet can be very harmful; continuously running toilets can cause the well to dry up and the pump to burn out, and inspectors should warn their clients of this danger.

  • Is the toilet taking too long to flush?

  • Is the toilet taking too long to fill?

  • the size of the water tank. According to a federal law passed in 1994, new toilets cannot use more than 1.6 gallons per flush (GPF). Toilets manufactured before 1994 are not subject to this law. The GPF is normally printed in one of the following locations: on a bowl; stamped on underside of tank lid; or on the inside of the tank.

  • connection between bowl and tank. When stepping on the bowl, the inspector can check that this connection is solid. Leaks can be caused by a weak connection.

  • the strength of the connection between the toilet bowl and the floor. Inspectors can test this connection by straddling the bowl and trying to rock it gently from side to side. A loose bowl can seep into the floor and cause wood rot on wood floors. Inspectors should recommend that bowls that are not firmly attached to the floor be re-attached.

Test for leaks.

A dye pill can be dropped into the water tank to see if the dye gets into the bowl without having to use the toilet. Inspectors can wait approximately 15 minutes after placing a dye pill in the tank to see if it has leached into the bowl. These pills are cheap and can be obtained for free from local waterworks.

A hygrometer is a useful tool for investigating whether water has leaked from the toilet to the surrounding floor.

Note: Inspectors should never use the water shutoff valve behind the toilet or any other water shutoff valve.

Cincinnati Home Inspections always involve a careful look at toilets.

Alternative toilet designs

Dual flush toilets, also known as duo sets, offer the user a choice of flushing. Two buttons allow the user to select between flushing for solid or liquid waste or 1.6 gallon and 1 gallon. Since most domestic flushing is for urine, dual flush toilets can save a significant amount of water, around 30%. This interactive toilet design helps conserve water and has quickly caught on in water-scarce countries such as Australia, where the dual-flush toilet was invented in 1980.

Unlike a septic system, which uses anaerobic (oxygen-free) bacteria to break down sewage and waste, composting toilets use aerobic (oxygen-using) bacteria and fungi, which do not require the waste to be covered with liquid. When properly configured and used, a composting toilet reduces waste to 10% to 30% of its original volume. The resulting product, called humus, is stable and resembles soil. In many areas of the world, humus is added to soil used for growing food, but the US prohibits this practice and requires that humus be disposed of according to the guidelines of the local Authority Having Jurisdiction (AHJ). Composting toilets use little or no water, require no expensive sewage systems, have little impact on the environment and are a valuable resource for gardening.

First produced by Fluidmaster, vacuum toilets provide a full, clean flush using only the rim holes inside the upper toilet bowl and lack the siphon nozzle hole at their base. When flushing, the water flowing out of the tank creates suction in the vacuum tank and trap, which helps to suck waste out of the bowl.

Auxiliary Pressure Toilets: The water supply of this toilet provides pressure to compress air in a sealed plastic reservoir inside the tank. When the incoming water reaches the fill line, the tank is pressurized and ready for the next flush. Although pressure-assisted toilets are somewhat noisy when flushing when the pressure is released, up to 80% of the flush water is used to flush the bowl, allowing for a very efficient flush. These toilets work well if the water pressure in the home is at least 25 pounds per square inch. Auxiliary pressure toilets can solve problems in homes with older plumbing systems where 1.6 gpf gravity fed toilets just aren't strong enough to pull the waste through the older pipes. Pressure toilets are generally better than typical gravity toilets, but the more complex mechanism makes them more expensive to purchase and repair.

Briefly, toilet defects include, but are not limited to: water leakage, cosmetic defects, and failure to flush contents.

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