Plumbers glossary
Short, plain-English definitions of the terms you'll meet when choosing a plumber provider in Ontario.
- What is a backflow preventer?
- A backflow preventer is a mechanical valve that blocks contaminated water or wastewater from flowing backward into the potable water supply.
- What is a backwater valve?
- A one-way check valve installed in a home's sewer line that prevents sewage and stormwater from backing up into the basement when municipal sewers become saturated or blocked.
- What is a cast iron drain pipe?
- Cast iron drain pipe is a heavy metal pipe material used for drainage in homes built before the 1970s in Ontario, which corrodes over decades and typically requires replacement.
- What is a cleanout?
- A cleanout is a removable cap or plug fitted to a drain line, providing access for plumbers to clear blockages and inspect pipes below the surface.
- What is a drain snake / auger?
- A drain snake or auger is a flexible, coiled metal cable tool used to remove clogs and obstructions from inside pipes by breaking them apart or retrieving debris.
- What is a P-trap?
- A P-trap is the U-shaped or S-shaped bend of pipe located below a sink, bathtub, or drain that holds a small amount of water to form a seal preventing sewer gases from entering the home.
- What is a pressure reducing valve?
- A pressure reducing valve (PRV) is a device installed on the main water line that automatically lowers incoming municipal water pressure to a safe operating range for household plumbing.
- What is a shut-off valve?
- A shut-off valve is a device that stops the flow of water to your entire home or to a single fixture, typically used during repairs or emergencies.
- What is a sump pump?
- A sump pump is an electric device installed in a pit below basement level that automatically activates to pump accumulated groundwater or surface water out of the home and away from the foundation.
- What is a tankless water heater?
- A tankless water heater heats water instantaneously as it flows through a heat exchanger, rather than storing hot water in a tank for later use.
- What is a TPR valve?
- A TPR valve (temperature and pressure relief valve) is a safety device on water heaters that opens to release excess pressure and heated water when either temperature or pressure inside the tank exceeds safe operating limits.
- What is a TSSA gas technician license?
- A TSSA gas technician license is the mandatory certification issued by Ontario's Technical Standards and Safety Authority that authorizes an individual to perform gas fitting work on appliances, piping, and heating systems.
- What is a vent stack?
- A vent stack is a vertical pipe that allows sewer gases to exit the building and maintains balanced air pressure in the drainage system to prevent water traps from emptying.
- What is ABS pipe?
- ABS (acrylonitrile butadiene styrene) pipe is a rigid black plastic tubing used for drain, waste, and vent applications in plumbing systems.
- What is an anode rod?
- A sacrificial metal rod, typically made of magnesium or aluminum, installed inside a water heater tank that corrodes to protect the tank steel from rust and extend the heater's life.
- What is an expansion tank?
- An expansion tank is a small pressure vessel that absorbs excess water volume created when water heats and expands in a closed plumbing system.
- What is combustion spillage?
- Combustion spillage is the escape of unvented exhaust gases from a gas appliance into living spaces instead of through the flue or vent system.
- What is copper pipe Type M vs Type L?
- Type M and Type L are residential copper water pipe grades that differ in wall thickness and maximum operating pressure, with Type M having thinner walls and Type L thicker walls for higher-pressure or underground applications.
- What is CSA certification?
- CSA certification is a Canadian Standards Association mark indicating that gas and plumbing appliances, fixtures, and fittings meet national safety and performance standards for legal use in Ontario.
- What is hydro jetting?
- Hydro jetting is a drain-cleaning method that propels water at high pressure (typically 3,000 to 4,000 PSI) through pipes to dislodge blockages, grease, mineral deposits, and buildup.
- What is PEX piping?
- PEX (cross-linked polyethylene) is a flexible plastic tubing used for hot and cold water distribution in residential plumbing systems, replacing copper pipe in many modern Ontario homes.
- What is sewer camera inspection?
- A video inspection technique that allows plumbers to view the interior of sewer and drain pipes to identify damage, blockages, and root intrusion without digging.
- What is the Ontario Building Code plumbing provision?
- The Ontario Building Code's plumbing provisions are the regulatory standards that govern the design, installation, and maintenance of plumbing systems in Ontario, based on the National Plumbing Code.
- What is water hammer?
- Water hammer is a loud banging or knocking sound in pipes that occurs when a valve closes suddenly and stops the flow of water, creating a pressure shock wave.