Backflow Prevention & Testing Services

Backflow prevention involves installing approved devices in your plumbing system that physically stop contaminated water from reversing direction and entering your clean drinking water supply. Without these devices, a drop in mains pressure or a rise in property-side pressure can draw whatever is connected to your system, including irrigation water, chemicals or pool water, back into the supply line. That contamination can reach your taps and, in some situations, spread further into the public network. Backflow prevention is required by law for many connection types in NSW precisely because the risk to public health is real.

For most installed backflow prevention devices, annual testing is a mandatory requirement under Sydney Water’s guidelines and NSW plumbing regulations. The exact frequency can vary depending on the device class and the hazard level of the connection, but annual as a minimum is the standard for RPZD, DCV and DCDA devices. Some high-hazard industrial installations may require more frequent testing. After each test, a signed certificate must be submitted to the relevant water authority.

Our certified plumber isolates the backflow device and connects calibrated differential pressure test equipment to the test cocks on the device. We check that each valve opens and closes correctly, measure the pressure differential across the device to confirm it meets the required minimum, and verify that any relief valves operate as designed. The whole process typically takes 30 to 60 minutes depending on the device type and accessibility. You receive a signed test report at the end, which you can submit to Sydney Water or retain for council compliance.

We provide upfront pricing before any work begins, so there are no surprises. Annual testing costs vary by device type, location and access difficulty. Repairs depend on what part has failed and the brand of device. We carry parts for the most common brands on our service vans, which keeps repair costs down by avoiding return visits. If a device is beyond economical repair, we will tell you clearly and provide a replacement quote before proceeding.

Backflow testing in NSW must be carried out by a licensed plumber who holds a specific backflow prevention endorsement. DIY testing is not accepted for compliance purposes, and test reports submitted by anyone other than an endorsed professional will not be recognised by Sydney Water or local councils. This requirement exists because backflow testing involves precise pressure measurement, and an incorrectly conducted test can produce a result that appears compliant when the device is actually failing.

Properties that require backflow prevention include those with in-ground irrigation systems connected to mains water, fire sprinkler or hose reel systems, swimming pools with mains top-up connections, commercial equipment such as dishwashers or cooling towers, and any connection involving chemicals or non-potable water. If you are unsure, we can conduct a risk assessment to determine exactly what your property needs. Sydney Water may also have placed a requirement notice on the property title if a backflow device was required at a previous stage.

The main types are Reduced Pressure Zone Devices (RPZD), Double Check Valve Assemblies (DCVA or DCV), Pressure Vacuum Breakers (PVB), Atmospheric Vacuum Breakers (AVB) and Dual Check Valves. The right device depends on the hazard rating of your connection. High-hazard connections such as chemical systems require an RPZD. Medium-hazard connections such as irrigation systems on commercial properties typically require a DCV. Low-hazard connections may be served by a dual check valve or vacuum breaker. Our plumbers assess the hazard level on site and specify the correct device class.

A standard residential backflow device installation takes between one and three hours depending on the device type and where it needs to be installed relative to your water meter and existing pipework. Commercial and industrial installations can take longer, especially where new pipe runs are required or the device needs to be installed in a confined space. We provide a time estimate as part of the quote so you know how long your water supply will be off during the installation.

Beyond the mandatory annual test, backflow devices benefit from periodic visual checks for external leaks, corrosion or physical damage. RPZD devices will occasionally drip from their relief valve during normal operation, which is expected, but a constantly running relief valve indicates an internal problem and needs attention. Devices should be protected from freezing in cold conditions and kept clear of vegetation or soil buildup that can trap moisture and accelerate corrosion. Our technicians provide a maintenance checklist specific to your device at the end of each testing appointment.

If your device fails testing, it must be repaired or replaced before it can be certified as compliant. In most cases we carry the parts needed to repair common device faults on the spot, so the repair happens the same day as the test. If the device is beyond repair, we remove it and install a replacement, then conduct an immediate post-installation test to certify the new device. You receive an updated compliance certificate once the repaired or replaced device passes. We notify you of the outcome and the required action before we do anything, so you are never charged for work you have not approved.