Cost Guide · Updated September 2026
How much does backflow testing cost in Perth?
What Water Corporation requires
In Perth, annual testing of every testable backflow device is mandated by Regulation 43 of the Water Services Regulations 2013 (WA). An endorsed plumber must carry out the test and lodge the certification with Water Corporation. No separate authority administration fee applies.
The reader arriving from a reminder notice: your deadline and device list are on the notice itself — the test below is what it costs to clear it.
Backflow testing prices — Perth 2026
| Service | Low | Typical | High |
|---|---|---|---|
| Annual backflow test (first device) | $150per device | $199 | $320 |
| Additional device (same visit) | $90per device | $120 | $145 |
| Budget test offers (verify call-out & lodgement included) | $80per device | $130 | $180 |
| Double check valve (DCV) install - 20mm | $650per device | $800 | $950 |
| RPZ valve install - 20mm | $1,250per device | $1,550 | $1,850 |
| RPZ valve install - 25-32mm (commercial / fire service) | $1,800per device | $2,500 | $3,200 |
| Tundish / drain for RPZ (add-on) | $220per install | $350 | $480 |
| Device repair (parts + labour) | $180per repair | $330 | $480 |
| Like-for-like replacement (failed device) | $550per device | $975 | $1,400 |
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Get Perth quotes →Prices include GST. Perth metro, September 2026.
A three-device site typically clears its annual visit for $330–$610 all up: $150–$320 for the first device plus two more at $90–$145 each. Budget offers below these bands usually exclude the call-out or the authority lodgement — ask before booking.
Frequently Asked Questions — Backflow Testing Cost in Perth
How much does a backflow test cost in Perth?
The annual test costs $150–$320 for the first device, with accredited flat-fee offers around $199 common. Additional devices tested on the same visit run $90–$145 each. GST included — verified September 2026 across 90+ sources.
How often does a backflow device have to be tested?
Every testable backflow prevention device (RPZ, double check valve or pressure vacuum breaker) must be tested every 12 months by a licensed plumber with a backflow testing endorsement, and the result lodged with your water authority.
What happens if I skip the annual test?
Authorities enforce it. In Sydney, Sydney Water’s 2026-27 schedule lists $553.12 where the annual test lapses and $431.68 where a tester cannot access the device; Queensland councils escalate unpaid program fees and reminders, and South Australia issues 30-day compliance notices. Supply interruption is the end of the road in most states.
What is the difference between an RPZ and a double check valve?
A double check valve (DCV) suits medium-hazard connections and costs $650–$950 installed at 20mm. A reduced pressure zone (RPZ) device protects high-hazard connections, needs a drain (tundish adds $220–$480) and costs $1,250–$1,850 installed at 20mm, or $1,800–$3,200 at commercial 25–32mm sizes.
Does backflow testing cost more in Perth?
The plumber’s test fee barely moves between capitals — published rates overlap in every city we track. What changes is the authority layer: who you lodge with, registration fees and what non-compliance costs. That is set by your water authority, not the market.