Managing a successful Perth business or commercial facility requires keeping track of dozens of moving parts. While aesthetics, customer service, and daily operations often take center stage, the hidden infrastructure behind the walls is what keeps a business viable. Among the most critical, yet easily overlooked responsibilities for any commercial property owner or manager are water safety and strict regulatory compliance.
At Harrington Plumbing & Gas, we work closely with Perth business owners, property managers, and strata bodies to ensure their commercial premises remain fully compliant, safe, and protected against costly operational disruptions.
Two of the most essential water compliance maintenance requirements for commercial properties are annual backflow prevention testing and Thermostatic Mixing Valve (TMV) servicing. Understanding the answers to a few core compliance questions is vital to protecting your commercial asset.
What Is Backflow Prevention Testing?
Backflow occurs when an unexpected drop in water pressure causes water from your commercial property to flow backward into Perth’s clean public mains. This reversal can pull hazardous chemicals, bacteria, industrial oils, or wastewater back into the shared drinking supply.
Think of a scenario where a water main bursts down the street, or the local fire brigade taps heavily into a nearby hydrant. The sudden drop in pressure creates a vacuum effect, siphoning water from your internal pipes back into the main line.
In simple terms, a backflow prevention device acts as a strict one-way safety valve, locking down your water system to protect the surrounding community from cross-contamination. What is backflow prevention testing exactly? It is a mandatory inspection process that ensures these mechanical valves are completely sealed and working perfectly under pressure.
The WA Water Corporation categorises commercial properties based on the level of potential contamination risk their operations pose to the main water supply. This rating determines the type of backflow protection required on-site.
| Risk Level | Description | Typical Examples |
| High Risk | Operations involving toxic chemicals, heavy manufacturing, or high-risk medical environments. | Chemical plants, hospitals, car washes, cooling towers, and pest control operators. |
| Medium Risk | Operations with a lower toxicity level but still containing harmful substances or greywater systems. | Commercial kitchens, laundromats, major office buildings, and manufacturing workshops. |
| Low Risk | Standard domestic connections with minimal risk of cross-contamination to the mains network. | Small retail shops, standard offices, and residential homes. |
How Often Do Backflow Preventers Need to Be Tested?
Because the potential risks to public health are incredibly high, backflow prevention devices must be tested and certified every 12 months. This is a strict legal mandate enforced by the WA Water Corporation for all properties with medium or high-risk ratings.
The utility provider tracks these registration details across Perth. Failing to submit an accredited plumbing report within the required timeframe can trigger formal warnings, heavy fines, and even the complete disconnection of your building’s water supply.
How to Test a Backflow Preventer: The Professional Process
When searching for how to test a backflow preventer, it is important to note that Western Australian law prohibits business owners or standard handymen from performing this task. Testing requires a licensed plumber with specialized backflow accreditation.
When our certified technicians handle your annual compliance check, they follow a rigorous diagnostic sequence using calibrated test kits to ensure the system is completely reliable.
Step 1: Visual and System Inspection
The technician isolates the device to inspect the outer assembly for physical wear, corrosion, cracks, or weeping water from the relief valves.
Step 2: Differential Pressure Testing
Using specialized calibrated testing gauges, we attach to the test cocks to measure the precise pressure drops across the internal check valves. This verifies that they close tightly and hold back any reverse water flow.
Step 3: Re-pressurisation and Verification
The water supply is safely restored to the property, and the device is checked under active operating pressure to confirm it is functioning perfectly.
Step 4: Official Water Corporation Lodgement
Once the device passes, we complete the mandatory compliance paperwork and officially lodge the digital test report directly with the WA Water Corporation on your behalf.
What Are Thermostatic Mixing Valves (TMVs)?
While backflow devices protect the water supply outside your business, Thermostatic Mixing Valves (TMVs) protect the people inside your building. Commercial hot water systems are legally required to store water at 60°C or higher to kill off harmful bacteria like Legionella. However, water at that temperature can cause severe third-degree burns within seconds, creating a massive safety hazard for anyone using the taps.
A TMV solves this problem by safely blending the hot water with cold water just before it reaches the outlet, delivering a consistent, safe temperature. This is usually set between 43°C and 50°C depending on your specific industry and building usage. Just like backflow devices, Australian standards mandate that these valves are mechanically tested and serviced every 12 months to guarantee they shut down instantly if the cold water supply fails, preventing any accidental scalding.
How Much Does a Backflow Prevention Test Cost?
A common question for property managers is how much does a backflow prevention test cost for a commercial site. The overall investment generally depends on a few specific variables:
- The size and model of the backflow prevention device
- The accessibility of the unit (whether it is underground, in a plant room, or at height)
- Whether the internal seals or rubber check valves need to be replaced to pass certification
- The number of devices installed across a single commercial layout or strata block
For most standard commercial properties in Perth, annual testing is a straightforward, highly predictable maintenance expense. Budgeting for a regular check is significantly cheaper than dealing with the legal penalties or emergency plumbing bills caused by a neglected system. Contact our team directly for an accurate, transparent quote tailored to your facility’s specific plumbing layout.
Professional Commercial Plumbing Testing in Perth
Managing commercial water compliance does not have to be complicated or time-consuming. At Harrington Plumbing & Gas, we provide streamlined, stress-free testing, maintenance, and official report lodging tailored to your specific business schedule. Our experienced team tracks your renewal dates and takes care of the technical heavy lifting, giving you total peace of mind and letting you focus entirely on running a successful business.
If your property is due for its annual water compliance check, working with a licensed commercial plumbing professional ensures your systems remain safe and fully accredited year after year.