Spa / Hot Tub Glossary (Australia)
This glossary of spa related terms is designed to help our clients who are new to the world of spas and hot tubs. Some words differ in Australia vs other parts of the world.
This glossary is currently being updated as we go.
Brands you might see in Australia: Davey (aka SpaQuip), SpaNet, Pentair, SpaPro, Balboa, AstralPool, Zodiac, WWDG, Gecko and more. (Brand examples are listed to help with identification and are not tied to any one definition below.)
Jet: Also called spa jet, hydro jet, massage jet. The fitting that directs water flow for massage action. Often made up of a jet body (in the shell) and a jet face/insert (the visible part).
Jet Body: Also called jet housing, jet socket. The main housing fitted through the spa shell that the jet insert/face locks into. Search Jet Body
Circulation Pump: Also called circ pump, filtration pump, recirc pump. A smaller pump used to circulate water through the filter and heater. May run on a schedule or continuously depending on the spa setup. Common across many systems including Balboa, Gecko and SpaNet based spas. Shop Circulation Pumps
Jet Pump: Also called boost pump, main pump, therapy pump. The larger pump that drives high flow to the jets. Many spas have one or more jet pumps (sometimes 1-speed or 2-speed).
Air Blower: Also called blower, spa blower, air pump, ring blower (side channel). Injects air into dedicated air lines to create bubbles. Not the same as an air control valve (venturi), which draws air in using water flow. . Search Air Blowers
Jet Diverter Valve: Also called diverter, selector valve. A valve (usually on the top side of the spa) that diverts water between two or more jet zones. Search Jet Diverters
Air Control Valve: Also called air control, venturi, air dial. Mounted on the lip of the spa or at the equipment shroud to induce air into the jets. Usually a partially rotating dial or handle. Search Air Controls
Filter Cartridge: Also called filter element, cartridge element. The removable pleated cartridge that captures debris and protects the equipment. Common in portable spas and many pool-adjacent setups. Search Filter Cartridges
Skimmer: Also called skimmer box, weir (sometimes), filter housing (some spas). The opening at the water line that draws surface water and debris into the filter area, usually via a floating gate/weir.
Suction: Also called suction fitting, intake, suction cover. The intake point where water is drawn from the spa into the circulation or jet pump(s). The term also refers to the suction plumbing line. Search Suction Parts
Touchpad: Also called topside, topside control panel, keypad, control pad, control panel, touchscreen (if touch). Mounted on the lip of the spa. The panel that controls the spa’s functions. Common controller ecosystems include Balboa, Gecko, Spanet, and Davey/Spa Power. Search Touchpads
Shell: Also called spa shell, acrylic shell. The main body of the spa that holds the water. Usually acrylic with fibreglass/composite reinforcement behind it. Shell designs vary widely across brands and ranges.
Heater Assembly (electric): Also called electric heater, heater tube, inline heater, flow-through heater. The thermostatically controlled heater that raises water temperature to your set point. Many packs (Balboa, Davey, Gecko, SpaNet and others) use sensors and safety devices integrated into the heater circuit. Shop Electric Heaters
Gas Heater: A heater that uses natural gas or LPG to heat pool or spa water. More common on pools and some larger spa setups. In Australia you’ll often see AstralPool and Pentair in this category, depending on the installation. Shop Gas Heaters
Control Box: Also called controller, spa pack, control pack, equipment pack. The “brain” of the spa. It distributes power to pumps, heater, blower, ozonator, lighting and other functions, and handles safety and fault codes. Common ecosystems include Balboa, Gecko, SpaNet and Davey/Spa Power. Search Control Boxes
Air Button: Also called pneumatic button, deck button. A button (usually on the spa lip) that sends air pressure through a small tube to activate an air switch. Shop Air Buttons
Air Switch: A pneumatic switch activated by an air button. Often latching (press on, press off). Common on spa baths and some older/retrofit setups. Search Air Switches
Check Valve: Also called one-way valve, non-return valve. Allows flow in one direction only. Commonly used on ozone lines to stop water backing up into the ozonator. Search Check Valves
Ozone Generator: Also called ozonator, ozone unit. Generates ozone gas used as a supplementary water treatment method to help reduce contaminant load. It does not replace correct sanitiser levels. Ozone setups are used across many spa brands and controller ecosystems.
Ozone Injector: Also called venturi injector, ozone mixer, injector tee (wording varies). The fitting that draws ozone gas into the water line (usually using venturi suction). Often paired with a check valve to prevent water backflow.
Drain: A fitting (often in the cabinet/equipment area) used to drain water from the spa.
Overtemperature switch: Also called hi-limit, high limit, overtemp, thermal cut-out, Klixon. A safety device that shuts heating down if temperature exceeds safe limits, or if there is a heating fault. Search Hi-Limits
PCB: Also called circuit board, printed circuit board, control board. The electronic board inside the controller that runs spa functions. PCBs are commonly referenced with controller brands like Balboa, Gecko, SpaNet and Davey/Spa Power. Search PCBs
Gate / Ball Valve: Shut-off valves used to isolate water lines for servicing. Gate valves are commonly the T-handle “slice” style used near spa equipment. Ball valves are more common in general plumbing/pool setups. Search Gate Valves
Mechanical Seal: The main water seal between the pump wet-end and the motor shaft. If it fails, water commonly drips from underneath the pump. Search Mechanical Seals
Seals O-Rings & Gaskets: Rubber seals used throughout spas to prevent leaks, including unions, lids, heaters and jet bodies. These vary a lot by brand and model, including popular AU ranges and private-label builds. Search O-rings & Gaskets
Barrel Union: Also called plumbing union, pump/heater union. The threaded collar (nut) and tailpiece assembly that connects a pipe to a component such as a pump or heater. Search Barrel Unions
Temperature Sensor: Also called temp sensor, thermistor, probe. Measures water temperature and reports it back to the controller. If faulty, spas can underheat, overheat, or show temperature/heat-related fault codes. Search Temperature Sensors
Helpful note: Many spas use OEM parts, and the same style of part can appear under different brand names. If you are matching a part, focus on photos, measurements, and how it connects (unions, threads, plug type) rather than brand labels alone.