What Happens When Consumer Reports Tests Toilets

Matthew is working with John Banta (in the back) because toilet testing requires two people: Each throne is about as unwieldy and heavy as a full-grown female Rottweiler—or 80 to 100 pounds for you cat people.

CR has been testing toilets since the ’80s and a lot of interesting stuff happens between the time the porcelain bowls roll into the lab to the moment updated ratings are published on our website.

The toilets are placed over holes cut into the platform. It’s elevated to give testers room to place a bucket and drain pipe under the toilets to catch whatever is flushed out.

The angled mirror is left over from the days when CR did toilet testing demonstrations for the public. Alas, people have since discovered Netflix.

The testers then hook up a waterline and fill ’er up to the waterline mark inside the tank. (Make sure your toilets at home are also filling to this waterline mark. If not, they might not be getting enough water to whisk away an entire load.)

The gadget above is called a flow meter. It measures the volume and flow of water into and out of the toilet. Most water-saving toilets claim to use 1.28 gallons per flush. Banta tells me that most of them use more—like 1.4 or 1.7 gallons—but still way less than the 6 gallons old toilets guzzled.

Which looks exactly like you’d imagine robot poop would look (if you imagine such things).

What the heck was this robot eating?

A combination of damp natural and synthetic sponges, some weighted with metal screws, mimic floaters. "The different size screws are intended to cause the sponges to float at different levels in the water,” says Jim Nanni, CR’s director of appliance testing, who developed these tests based on scientific studies that looked at artificial fecal matter with high clog potential.

The shape, density, and size of the polyethylene balls remind me of constipated poop. (That’s one very relieved robot!)

Water filled condoms stand in for a soft, easy stool. They’re not lubricated (don’t want to make it too easy to slip through).

The difficult dump is a doozy: 160 polyethylene balls, 7 sponges, and 2 water-filled condoms. Banta says few toilets can gobble the difficult load in one go. "That’s how we’re able to get the differentiating data we use to score each toilet," he says.

Testers dump a “difficult” load into the toilet. And then comes the moment of truth . . .

After one flush, 109 balls, six sponges, and 1 water-filled condom remain. (Testers determine this by counting what’s flushed out.)

After three flushes, we still have 92 balls and 6 sponges hanging around which means we’ve got a clog. How’s this toilet rating so far? Kind of, eh, crappy.

“This is why people should courtesy flush,” Banta says. “Breaking up the load is just common sense.”

Don’t worry, we don’t dump our robot poop into the sewer. Those bits and bobs are caught in this sieve with each flush, counted, and then re-used by the testers.

When toilets clog, Guayara whips out the plunger. (He says he likes the accordion-style because they pump water and also fit in all types of toilet shapes.)

Which requires a ride on the lavatory lift.

This rig is much higher to accommodate the pitch angle of the drain line, which is made of clear plastic piping and wraps 75 feet around the lab, incorporating three elbows and two S-turns.

The pipes are clear so testers can see how well a toilet would move waste from bowl to sewer and whether there’s enough force to make sure nothing gets stuck. A low rating in this test means the toilet might be more prone to clogging your drain pipes.

Banta measures how far each sponge moves down the tube. (He installed LED lights in the pipes for better visibility, inadvertently adding a Space Odyssey feel to this test.) No sponges make it all the way through on the first flush, which is normal—the test needs to be somewhat more challenging than the plumbing in homes to allow our ratings to be comparative. 

The next tests are more mundane, but no less important.

Guayara measures the height of each toilet’s seat and notes which ones are compliant with Americans With Disabilities Act guidelines (at least 16 inches high at the seat). We measure with the seat on if the toilet comes with one (did you know that most don’t?). The bum ticklers—we’re talking about bidet seats here, people!—are unfortunately always sold separately.

Bowl measurements help gauge soil and odor potential. Dying the water helps testers take accurate and fast measurements. You’ll find this info in the Features & Specs section of each review in our toilet ratings. Deeper and wider = less stink and stick potential because there’s more room for waste to be covered by water, which helps trap odors and prevent messes.

Guayara applies acrylic paint in “cottage red” on a dry spot in the bowl and flushes twice to see how much paint is removed. The front of the bowl is the most challenging spot for a toilet to clean, especially with elongated models. “Not all waste is deposited to the rear of the bowl where it’s deep,” Nanni says. “Think of a child teetering off the front edge of the seat or an adult depositing their stomach contents due to illness or a night of drinking.” 

Party potty tip: “If you’re at a party and make a mess of the toilet bowl, just hold down the handle while flushing to keep the water flowing,” Banta says. He adds that a pre-flush before you do your business can save you from embarrassment because poop is less likely to stick to a wet bowl than a dry one.

Testers also evaluate cleaning ability by drawing a line around the bowl about an inch under the rim with a water-soluble marker. The fewer markings left after flushing, the better a toilet cleans.

For this test, they place a decibel meter outside a makeshift doorless plywood stall. Most toilets flush at about 70 to 74 decibels. The ones with pressure assist provide more oomph and more volume: about 85 decibels (louder than a typical vacuum cleaner). They also tend to clog less than conventional models.

What’s Banta’s biggest toilet takeaway after years of testing them? "Brand or price don’t necessarily correlate with performance," he says. Your best bet? Check out our toilet buying guide and ratings before making a purchase. Your plumbing will thank you!