Plumbing Trivia
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100 free Plumbing trivia questions with answers — technology quiz, new questions added Oct 2026.
42 free Plumbing trivia questions with answers. Plumbing is one of the oldest trades and one of the least celebrated, so this quiz gives it its due. It covers the Roman lead pipes that gave the profession its name, the Indus Valley drains that predate them, the Elizabethan courtier who built a flush toilet for the queen, the Scottish clockmaker who patented the S-trap, and the London engineer whose sewers ended cholera in the capital. It also asks how a P-trap works, what PEX and PVC are, why plumber's tape is used, who invented the plunger and the pipe wrench, and what a 130-ton fatberg is made of. Easy questions suit anyone who has ever fixed a running toilet; the harder ones are for tradespeople, apprentices and history buffs, with a few detours into Mario, Joe the Plumber and Japan's Washlet. It works for an apprentice class, a trade-show booth or a pub round for the building crew. Every answer has been checked against Wikipedia and reference sources, and each question shows an explanation and its citation once you answer.
30 of 100 questions with answers and explanations. Play the quiz
Q 01The word plumber comes from the Latin plumbum, which means what?
Lead
The first effective pipes in the Roman era were made of lead, and the metal's chemical symbol Pb comes from the same root.
Q 02Standardised earthenware pipes with sealed flanges appeared by 2700 BC in which civilisation?
The Indus Valley
The Indus Valley cities used standardised earthenware pipes with broad flanges, sealed with asphalt against leaks, by about 2700 BC.
Q 03Rome's first aqueduct, the Aqua Appia, was built in which year?
312 BC
The Aqua Appia was built in 312 BC by the censor Appius Claudius Caecus, who also began the Appian Way that year; the city eventually had eleven aqueducts.
Q 04The Cloaca Maxima, one of the world's oldest sewers, served which ancient city?
Rome
The Cloaca Maxima drained Rome's Forum valley, beginning in the sixth century BC as an open canal under the Tarquin kings; its outfall into the Tiber survives.
Q 05The Roman hypocaust was an early form of what?
Underfloor central heating
Hot air from a furnace circulated beneath raised floors and up through wall pipes, a forerunner of modern central heating.
Q 06Sir John Harington, who described a flush toilet in 1596, installed one for which royal godmother?
Elizabeth I
Harington's godmother Elizabeth I had the device installed at Richmond Palace; his 1596 book describing it was A New Discourse of a Stale Subject, called the Metamorphosis of Ajax.
Q 07Who patented the S-trap, the bend beneath sinks and toilets, in 1775?
Alexander Cumming
Alexander Cumming, a Scottish watchmaker, patented the S-trap in 1775, the key step toward the modern flush toilet; Bramah improved the mechanism three years later.
Q 08Joseph Bramah, who patented the first practical flush toilet in 1778, is also famous for inventing what?
The hydraulic press
Joseph Bramah patented the hydraulic press in 1795, applying Pascal's principle to multiply force; he was also a celebrated locksmith whose challenge lock went unpicked until 1851.
Q 09Which of these is true of Thomas Crapper?
He patented the floating ballcock
The English plumber's fame was inflated by a 1969 satirical biography, and the word crap is Middle English, older than his career.
Q 10What is the purpose of the U-shaped trap under a sink?
To hold water that blocks sewer gases
The trap holds standing water that blocks sewer gases from rising into the room; if that seal evaporates in an unused drain, the smell of the sewer comes straight through.
Q 11In a drain-waste-vent system, what is the job of the vent pipe that runs up through the roof?
To stop a vacuum forming in the pipes
Without venting, draining water can siphon the traps dry and let sewer gas into the house.
Q 12The ballcock in a toilet cistern gets its name from what?
The ball-shaped float on its lever
The name comes from the ball-shaped float on its lever: as the water rises the ball lifts the arm and closes the fill valve, preventing overflow.
Q 13The banging noise in pipes when a tap is shut off suddenly is known as what?
Water hammer
Q 21The Washlet, the electronic bidet seat found across Japan, is made by which company?
Toto
Toto, the Kitakyushu-based sanitaryware maker, launched the Washlet in June 1980, and its 1982 'even bottoms want to be washed' television campaign made it a Japanese household name.
Q 22The word bidet originally referred to what in French?
A small horse
Bidet was French for a small horse or pony, and the fixture took the name because one straddles it as if riding.
Q 23The 1858 Great Stink, which drove Parliament to act on sewage, was caused by the smell of which river?
The Thames
The hot summer of 1858 cooked untreated sewage on the Thames's banks until the stench reached the Commons, whose curtains were soaked in chloride of lime.
Water hammer is a pressure surge from moving water stopping abruptly; a water hammer arrestor, an air- or piston-cushioned chamber, absorbs the shock.
Q 14PEX, the flexible red and blue tubing used in home water lines, is short for what?
Cross-linked polyethylene
PEX stands for cross-linked polyethylene; the cross-linking greatly improves impact strength and resistance to stress cracking compared with ordinary polyethylene.
Q 15White plumber's tape wrapped around threaded joints is made of which material?
PTFE
Thread seal tape is PTFE (polytetrafluoroethylene), the fluoropolymer sold under the Teflon name; it lubricates the threads and fills gaps to seal the joint.
Q 16The Stillson wrench, the classic pipe wrench, was created by a mechanic at which Massachusetts firm?
Walworth
Daniel Stillson, a mechanic at the Walworth Manufacturing Company, a Boston steam-fitting firm, devised the wrench in the late 1860s and licensed his patent widely.
Q 17The plumbing plunger was invented in 1874 by John Hawley, a New Yorker in what line of work?
Confectioner
John Hawley, a New York confectioner, patented the plunger in 1874; the flattened rim followed two years later, and the tool is also called a force cup or plumber's friend.
Q 18The first Roto-Rooter machine, built in 1933, was powered by the motor from what?
A washing machine
Samuel Blanc of Des Moines, Iowa built it around a Maytag washing machine motor after clearing a root-blocked sewer at his son's apartment, and founded the Roto-Rooter company on it.
Q 19The 'septic' in septic tank refers to what?
The anaerobic bacteria inside it
'Septic' refers to the anaerobic bacteria inside the tank, which break down the solids without oxygen; the tank gives only primary treatment before liquid flows to a drain field.
Q 20The Kohler company made its first bathtub in 1883 by applying enamel to what?
A cast-iron horse trough
John Michael Kohler, an Austrian immigrant who had founded the Wisconsin firm in 1873, baked enamel onto a cast-iron horse trough and hog scalder, added four feet, and sold it as a bathtub.
Q 24Which engineer built London's main drainage system in response to the Great Stink?
Joseph Bazalgette
Joseph Bazalgette, chief engineer of the Metropolitan Board of Works, built 82 miles of intercepting sewers that ended London's cholera outbreaks and created the Victoria, Chelsea and Albert Embankments.
Q 25The 2017 Whitechapel fatberg found under London weighed about how much?
130 tonnes
Thames Water put the Whitechapel fatberg at about 130 tonnes and 250 metres long, as heavy as eleven double-decker buses; a chunk went on display at the Museum of London in 2018.
Q 26Fatbergs form when fat, oil and grease combine with what flushed item in particular?
Wet wipes
Wet wipes, even those sold as flushable, do not break down like paper; they snag and bind with congealed fat, and utilities run 'bin it, don't flush it' campaigns against them.
Q 27The Tremont House in Boston, opened in 1829, is best remembered as the first hotel with what?
Indoor plumbing and running water
The Tremont House pioneered indoor plumbing and running water, with eight water closets on the ground floor and basement bathrooms supplied with cold running water, plus free soap in every room.
Q 28The 2014 water crisis in Flint, Michigan began when the city switched its supply from Lake Huron to what?
A local river
Officials failed to add corrosion inhibitors, so lead leached from old pipes and exposed about 100,000 people.
Q 29Hard water, which leaves limescale, is rich in dissolved compounds of which two elements?
Calcium and magnesium
Hard water carries dissolved calcium and magnesium salts, which precipitate as limescale when heated; a water softener swaps those ions for sodium using an ion-exchange resin.
Q 30The US Energy Policy Act of 1992 capped new toilets at how many gallons per flush?
1.6
The Act limited new toilets to 1.6 gallons per flush from 1994, down from the 3.5 gallons then typical; early low-flow models were mocked for needing a second flush.