Plumbing Glossary & Homeowner Guide

Plain-language definitions for 100 plumbing terms. Understand what a plumber is talking about, what a component does, and when to call.

This glossary explains common plumbing components and concepts in plain language. Each definition covers what something is, what it does, and what goes wrong when it fails. For diagnosis guides that explain why something is happening in your home, visit Common Plumbing Problems. For services, visit our Services page.

Water Heaters

T&P Relief Valve

Also: T&P valve, TPR valve

Water Heater Anode Rod

Also: sacrificial anode

Water Heater Expansion Tank

Also: thermal expansion tank

Water Heater Heating Element

Also: immersion element

Water Heater Thermostat

Also: temperature control

Water Heater Drain Valve

Also: tank drain spigot

Water Heater Sediment

Also: limescale, mineral deposits

Pilot Light

Also: standing pilot, pilot flame

Thermocouple

Also: thermopile, pilot safety sensor

Water Heater Burner

Also: gas burner assembly

Dip Tube

Also: cold water dip tube

Tankless Water Heater

Also: on-demand water heater

Heat Exchanger

Also: condensing heat exchanger

Gas Control Valve

Also: combination gas valve

Water Heater Tank

Also: storage water heater, hot water tank

Drains & Sewer

P-Trap

Also: drain trap, sink trap

Plumbing Vent

Also: vent pipe, drain vent

Vent Stack

Also: main vent stack, soil stack vent

Main Sewer Line

Also: sewer main, house sewer line

Sewer Cleanout

Also: cleanout plug, drain cleanout

Sewer Camera Inspection

Also: drain camera, sewer scope

Hydro Jetting

Also: high-pressure drain cleaning

Drain Snake

Also: plumber's snake, hand snake

Drain Auger

Also: toilet auger, closet auger

Tree Root Intrusion

Also: root infiltration, roots in pipes

Trenchless Sewer Repair

Also: no-dig sewer repair

CIPP Pipe Lining

Also: cured-in-place pipe lining

Sewer Backup

Also: sewage backup, drain backup

Sewer Gas

Also: sewer smell, drain gas

Biofilm

Also: drain slime, organic buildup

Floor Drain

Also: basement floor drain, utility drain

Drain Trap

Also: pipe trap, water seal trap

Branch Drain

Also: branch line, fixture drain

DWV System

Also: drain-waste-vent system

Soil Stack

Also: soil pipe, waste stack, main stack

Basement & Sump Pumps

Sump Pump

Also: submersible sump pump

Sump Pit

Also: sump basin, sump well

Sump Pump Float Switch

Also: float switch, sump float

Sump Pump Check Valve

Also: pump check valve, one-way valve

Sump Pump Discharge Line

Also: discharge pipe, pump outlet

Battery Backup Sump Pump

Also: DC backup pump

Hydrostatic Pressure

Also: groundwater pressure, soil water pressure

Basement Floor Drain

Also: utility drain, laundry drain

Backup Sump Pump

Also: secondary sump pump

Sump Pump Alarm

Also: high-water alarm, water level alarm

Pipes & Water Supply

Main Water Shutoff Valve

Also: main shutoff, house shutoff

Pressure-Reducing Valve (PRV)

Also: PRV, pressure regulator

Water Hammer

Also: hydraulic shock, pipe banging

Water Hammer Arrestor

Also: hammer arrestor, shock absorber

Water Supply Line

Also: supply line, braided supply line

Water Service Line

Also: service lateral, supply lateral

Pipe Corrosion

Also: corroded pipes, pipe rust

Scale & Mineral Buildup

Also: limescale, calcium buildup

Hard Water

Also: high mineral content water

PEX Pipe

Also: cross-linked polyethylene, PEX tubing

Copper Pipe

Also: copper plumbing, Type L copper

PVC Pipe

Also: polyvinyl chloride pipe

Cast-Iron Pipe

Also: CI pipe, cast iron soil pipe

Galvanized Pipe

Also: galvanized steel pipe

Water Pressure

Also: household water pressure, tap pressure

PSI

Also: pounds per square inch

Water Meter

Also: utility water meter

Leak Detection

Also: plumbing leak detection

Slab Leak

Also: under-slab leak, foundation pipe leak

Repiping

Also: whole-house repipe, replumbing

Rough-In Plumbing

Also: plumbing rough-in

Ball Valve

Also: quarter-turn valve

Gate Valve

Also: multi-turn gate valve

Check Valve

Also: one-way valve, non-return valve

Compression Valve

Also: angle stop, stop valve

Toilets, Faucets & Fixtures

Toilet Flapper

Also: flush valve flapper, tank flapper

Toilet Fill Valve

Also: ballcock, toilet refill valve

Toilet Float

Also: float ball, tank float

Toilet Wax Ring

Also: wax seal, toilet base seal

Toilet Flange

Also: closet flange, floor flange

Toilet Trapway

Also: toilet trap, toilet S-trap

Faucet Cartridge

Also: mixer cartridge, valve cartridge

Faucet Aerator

Also: tap aerator, faucet screen

Fixture Shutoff Valve

Also: supply stop, angle stop

Plumbing Fixture

Also: fixture, sanitary fixture

Backflow & Exterior Plumbing

Backflow

Also: back-siphonage, cross-connection

Backflow Preventer

Also: RPZ valve, backflow assembly

Vacuum Breaker

Also: atmospheric vacuum breaker, AVB

Irrigation Backflow Preventer

Also: sprinkler backflow preventer

Frost-Free Hose Bibb

Also: freeze-proof sillcock

Hose Bibb

Also: sillcock, outdoor faucet, spigot

Septic Systems

Septic Tank

Also: on-site sewage tank

Drain Field

Also: leach field, soil absorption field

Septic Baffle

Also: inlet baffle, outlet baffle

Septic Effluent

Also: effluent, treated sewage

Wells & Water Treatment

Well Pump

Also: water well pump, residential well pump

Pressure Tank

Also: well pressure tank, bladder tank

Pressure Switch

Also: pump pressure control

Submersible Well Pump

Also: deep well pump, submerged pump

Well Water Pressure

Also: private well pressure

Water Softener

Also: ion exchange softener, salt-based softener

Water Hardness

Also: grains per gallon, GPG

Ion Exchange

Also: cation exchange, softening resin

Reverse Osmosis

Also: RO system, RO filter

Sediment Filter

Also: whole-house sediment filter, spin-down filter

A–Z Index

Anode Rod (Water Heater)

Expansion Tank (Water Heater)

Leak Detection

Have a Plumbing Problem?

Gray's Precision Plumbing diagnoses and repairs plumbing problems throughout Northeast Ohio. Call or text for a straight answer on what's happening and what it will take to fix it.

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