• ADA:  Abbreviation for Americans with Disabilities Act standards. These standards ensure bathroom and kitchen facilities are accessible to people with disabilities.
  • Access Panel: A removable door or panel installed in a wall, ceiling, or floor that allows easy access to hidden plumbing components.
  • Aerator: Mixes air with water to create a softer, aerated stream for a faucet.
  • Air Gap: A space that physically prevents contaminated drain water from siphoning back into the clean water supply.
  • Angle Stop: 
  • Anode Rod: Sacrificial metal rod installed inside the tank of an electric water heater. It protects the steel tank from corrosion through a process called electrolysis.


  • Back Flush: The process of reversing the water flow through a pipe, filter, or other component. The main purpose is to clean the water by removing debris.
  • Ballcock: Used to control the water level in a toilet tank, like a fill valve.
  • Basin: A bowl-shaped fixture in your kitchen or bathroom, usually in the form or a sink. Alternatively, a floor drain designed to collect and drain wastewater.
  • Basket Strainer: A detachable device that can be placed in the drain opening of a sink to capture debris and prevent it from going down a drain.
  • Bidet: A plumbing fixture that sprays water for personal cleaning after using the toilet. Some may also have a drying feature.
  • Bidet Seat: A self-contained bidet that replaces your toilet seat, adding a spray function for post-toilet hygiene.
  • Bird Screen (water heater accessory): Mesh screen installed on the vent pipe termination to prevent birds and other animals from getting into the pipe.
  • BTU (British Thermal Unit): Used to measure heat, specifically the amount needed to raise the temperature of one pound of water by one degree Fahrenheit.
  • Buchan Trap: Also known as a house trap, it is used to prevent sewer gases and odors from entering a building. While they might still be encountered in older buildings, they are not typically used in new construction.


  • Cast Iron: Material used for drain, waste, and vent (DWV) systems. It can also be used in a variety of pumps.
  • CeFiONtect: A super-smooth glaze applied to Toto ceramic toilets. It creates a non-stick surface that repels waste and makes cleaning easier.
  • Centerset: Faucet where two handles are spaced apart by a standard distance, typically 4 inches, around a central spout.
  • Cleanout (C/O): A location where the interior of a pipe can be accessed to clear out clogs. Cleanouts are generally located on the side of the house.
  • Closet Flange: A toilet flange, a pipe fitting that allows for securing the toilet and making a drainage connection to the drain system in the house.
  • Combination Boilers: Also known as a combi boiler, a combination boiler is a single heating unit that functions as both a boiler and a tankless water heater.
  • Condensing Boiler: An efficient heater that delivers more heat out per fuel by capturing heat from exhaust.
  • Copper: In plumbing, copper refers to a type of tubing or pipe used for hot and cold water lines due to its durability, resistance to corrosion, and ability to kill bacteria.
  • Coupling: A connector for pipes.
  • CPVC: Chlorinated PolyVinyl Chloride
  • CW: Abbreviation for cold water.
  • CWP: Abbreviation for cold water pressure.
  • CWT: Abbreviation for cold water tube.
  • CxC: Abbreviation for copper x copper.
  • Cycle Time: The time it takes for a toilet to complete a flush cycle.


  • Diverter: A valve that controls the direction of water flow.
  • Drain: A pipe or system of pipes that carries unwanted water or waste liquids away.
  • Dual Flush: A toilet that has two flush options, the first that uses less water for liquid waste and the second that uses more water for solid waste.
  • DWV: Abbreviation for drainage, waste, and vent.
  • Dynamic Pressure: Refers to the pressure exerted by moving water within the pipes. 


  • Effluent: Liquid waste that has already been processed.
  • Elongated: Oval shape of a toilet bowl that is wider at the front than at the back. Elongated bowls offer more comfort and extra legroom compared to round toilet bowls.
  • Enamel: Hard, glossy coating applied to metal fixtures, most commonly cast iron sinks and bathtubs
  • Escutcheon: Decorative cover plate that hides the hole around a pipe where it enters or exits a wall, floor, or ceiling.
  • Expansion Tank (for water heater): A pressure relief device for closed system water heaters. It absorbs extra pressure caused by hot, expanding water to protect the system from damage.



















  • Water Closet (closet, commode, toilet): An old-fashioned term for a toilet.