Why Knowing Plumbing Terms Matters When you call a plumber to describe a problem, the words you use make a big difference. A clear description helps your plumber understand the issue before they arrive, bring the right tools and parts, and give you a more accurate quote over the phone. You don't need to be an expert — but knowing the basics can save you time, money, and frustration. We've put together this plain-English guide to the most common plumbing terms you'll encounter when booking a job or discussing repairs with your plumber. Bookmark this page — it'll come in handy next time you need to make that call. General Plumbing Terms Isolation Valve (Shut-Off Valve) A valve that stops water flow to a specific fixture (toilet, sink, washing machine) or to your entire house (main shut-off valve). When you call and say "I've isolated the water," your plumber knows you've turned off the relevant valve — that's helpful information. Mains Water The water supplied to your property from Sydney Water's street supply. When your plumber asks about your "mains pressure," they want to know about the water pressure coming from the street, not from your internal pipes. Backflow When water flows in the wrong direction — backwards through your pipes. This can contaminate your clean water supply with dirty water. A backflow prevention device stops this from happening. Sydney Water requires these on many properties. Water Hammer That loud banging or knocking sound your pipes make when a tap is turned off quickly. It's caused by the sudden stop of water flow creating a shockwave in the pipes. It's not just annoying — over time it can damage pipe joints and fittings. Tempering Valve (TMV) A valve that mixes hot and cold water to deliver water at a safe temperature (usually 50°C) to prevent scalding. Australian regulations require these on hot water systems. If your hot water is too hot or too cold, the tempering valve might need adjusting or replacing. Drainage and Sewer Terms Trap (P-Trap, S-Trap) The curved section of pipe under your sink, shower, or basin that holds water to create a seal. This water seal prevents sewer gases from entering your home. If you smell sewage, the trap may have dried out or be damaged. When booking, you might say: "There's a bad smell coming from the drain under my bathroom sink — I think the trap might be the issue." Overflow Relief Gully (ORG) A floor-level drain, usually outside your house, designed to release sewage overflow outdoors rather than inside your home. It has a grate that sits slightly below ground level. If you see sewage bubbling up through a drain outside your house, that's your ORG doing its job — but it means your sewer is blocked and needs immediate attention. Sewer Line vs Stormwater These are two completely separate drainage systems, and mixing them up is a common mistake. Your sewer line carries wastewater from toilets, sinks, and showers to Sydney Water's mains sewer. Your stormwater system carries rainwater from your roof, gutters, and yard drains to the street or stormwater channel. They should never be connected to each other. Jet Blasting (High-Pressure Water Jetting) A method of clearing blocked drains using a high-pressure water jet. A specialised nozzle is inserted into the pipe and blasts water at up to 5,000 PSI to cut through tree roots, grease, and debris. When you call and say "I think I need my drains jet blasted," your plumber knows the blockage is likely severe. CCTV Drain Inspection A small waterproof camera on a flexible cable is fed into your drain pipes to see exactly what's happening inside. This lets the plumber diagnose the problem accurately without guesswork or unnecessary digging. We can show you the footage in real-time on a screen. Pipe Relining A no-dig method of repairing damaged pipes by inserting a resin-coated liner inside the existing pipe. The liner hardens to form a new pipe within the old one. This avoids digging up your yard, driveway, or garden. When you hear "relining," think "repair from the inside." Hot Water Terms Storage System vs Continuous Flow (Instantaneous) Storage systems heat and store a tank of water (typically 125-400 litres) ready for use. Continuous flow (also called instantaneous or tankless) systems heat water on demand as it passes through the unit — no tank, no stored water. Knowing which type you have helps your plumber diagnose issues and bring the right parts. Anode Rod (Sacrificial Anode) A metal rod inside your storage hot water tank that corrodes instead of the tank itself, protecting the tank from rust. When the anode rod is completely corroded, the tank starts rusting and will eventually fail. Replacing the anode rod every 5 years can double the life of your hot water system. TPR Valve (Temperature and Pressure Relief Valve) A safety valve on your hot water system that releases water if the temperature or pressure gets too high. If you see water dripping from a small copper pipe on the side of your hot water tank, that's the TPR valve — and it might need attention. Never block or cap this valve; it's a critical safety device. Fixture and Fitting Terms Cistern The water tank on the back of your toilet. When you say "my toilet keeps running," the problem is usually inside the cistern — either the inlet valve, the outlet valve (flush valve), or the float mechanism. Mixer Tap vs Pillar Taps Mixer taps have a single spout with one handle (or two handles) that blends hot and cold water. Pillar taps are separate hot and cold taps with individual spouts. Knowing which type you have helps when ordering replacement parts. Flexi Hose (Braided Connector) The flexible, braided stainless steel hoses that connect your taps, toilets, and appliances to the water supply. These are the number one cause of internal flooding in Australian homes when they fail. They should be replaced every 10 years. If you see rust stains, bulging, or kinking on your flexi hoses, call your plumber immediately. Flange A flat ring that connects two pipes or connects a pipe to a surface (like the toilet to the floor). If your toilet is leaking at the base, the wax ring or flange seal may need replacing. Gas Plumbing Terms Gas Compliance Certificate A legal document issued by a licensed gas fitter after installing or modifying gas appliances. It certifies the work meets Australian Gas Standards (AS/NZS 5601). You need one for insurance purposes and when selling your home. Gas Isolation Valve A valve that shuts off gas supply to a specific appliance or to your entire property. If you smell gas, turn off the gas isolation valve, open windows, leave the area, and call your gas plumber and the gas emergency line. How to Describe Your Problem When Calling a Plumber When you call Optimised Plumbing Services, here's a template for describing your issue effectively: What's happening? — "Water is leaking from under the kitchen sink" is much more helpful than "there's a plumbing problem." Where is it? — Be specific: "the downstairs bathroom toilet" or "the kitchen mixer tap." When did it start? — "It started this morning" vs "it's been getting worse for months" changes how urgently we respond. How bad is it? — "A slow drip" vs "water is pouring out" helps us prioritise and prepare. What have you done? — "I've turned off the isolation valve under the sink" tells us you've contained the issue. Any relevant history? — "We had the same drain blocked last year" or "the hot water system is about 12 years old" gives us context. Understanding Your Plumber's Quote When your plumber gives you a quote, here are some common line items you might see: Call-out fee — A fixed fee for the plumber to travel to your location and assess the problem. At Optimised Plumbing, this is applied to the job if you proceed with the work. Labour — The cost of the plumber's time, usually charged per hour or as a fixed price for the job. Materials — Parts, pipes, fittings, and supplies needed for the repair. CCTV inspection — If a camera inspection is needed to diagnose a drainage issue. Disposal fees — For removing old fixtures like hot water systems or broken pipes. At Optimised Plumbing Services, we believe in transparent, upfront pricing with no surprises. Call us on 02 8000 1058 — and now you'll know exactly how to describe what's going on.