Backflow Prevention Testing & Repairs
Tap Doctor Plumbing & Gas, trusted since 1985
Licensed plumbers for backflow device testing, servicing, repairs and installation at homes and businesses. We agree a firm price before we pick up the tools, and there’s no call-out fee during business hours.
- 1Tell us what needs doing
- 2Pick a day and time that suits
- 3We confirm and send a licensed Tap Doctor plumber
- 4Job done, problem solved
- Trusted since 1985
- Fully Licensed & Insured
- No call-out fee in business hours
- Locally Based Plumbers
- ★★★★★2,000+ Google reviews
- Trusted since 1985
- Licensed plumbers, fully insured
- Homes and businesses
- Phones answered 24/7
What backflow is, and why devices are tested
Backflow is water running the wrong way: from a property back into the mains drinking water supply. A backflow prevention device stops it, but like any valve it can wear or stick, which is why testable devices are checked every year.
How backflow happens
- Back-pressure: a pump, boiler or raised tank on the property pushes water above mains pressure, so it flows back towards the main.
- Back-siphonage: mains pressure drops, for example during a burst water main, and water is drawn back out of the property.
- Cross connection: a hose left in a pool, a chemical dosing line or a tank linked to mains plumbing gives that water a path into the supply.
Properties that commonly need a testable device
- Shops, offices, cafes and commercial kitchens
- Medical, dental and veterinary practices
- Sites with fire hose reels or fire sprinklers
- Irrigation systems that inject fertiliser or chemicals
- Homes with a rainwater tank or bore connected to mains plumbing
- Pools, spas and water features with a mains top-up
Your water supplier or council sets which device your property needs and how often it’s tested.
Call 24/7: 1300-655-827Backflow testing, repairs and installation
Our licensed plumbers test, service, repair and install backflow prevention devices at homes, shops, offices and commercial sites. These are the backflow jobs we’re called for most.
Annual backflow testing
Each testable device is checked with a test kit: every check valve and relief valve is tested to make sure it opens, closes and holds pressure as it should. We explain the result for each device and tell you if anything needs fixing.
Backflow device repairs and servicing
When a device fails its test it usually needs new seals, springs or a check valve. We service or repair it, then retest it so you know it’s working before we leave.
New backflow device installation
The right device for the hazard rating of the property, from dual check valves to double check valve assemblies and reduced pressure zone devices, fitted with isolation valves so it can be tested and serviced later.
Replacing old or failed devices
Devices that are corroded, leaking, can’t be repaired or are no longer the right type for the property are replaced, and the new device is tested once it’s in.
Tanks, bores, pools and irrigation
Backflow protection where a rainwater tank or bore is connected to mains plumbing, on pool and spa top-up lines, and on reticulation that injects fertiliser.
Commercial backflow More →
Testing and device work for shops, offices, restaurants and commercial kitchens, booked around your trading hours where possible.
Why people call Tap Doctor for backflow work
A backflow device protects the water everyone drinks, so the testing has to be done properly. This is how we handle every backflow job.
Licensed plumbers
Backflow devices are tested, serviced and installed by licensed plumbers, and every device is retested after a repair.
A firm price before any work starts
Your plumber looks at the devices, explains what’s needed and gives you a firm price. Nothing starts until you agree.
No call-out fee in business hours
You don’t pay for us to turn up and look. If you decide not to go ahead, you owe nothing during business hours.
We call ahead and arrive on time
We confirm your booking, then call before we arrive so you’re not waiting around all day.
Homes and businesses
From a single device at a house to several devices across a commercial site.
Pay when the job is done
Cash, card or Osko bank transfer, collected when the work is finished.
How pricing works
What does backflow testing cost? It depends on how many devices you have, what type they are, how easy they are to get to and whether anything needs repairing. Instead of guessing, a licensed plumber looks first and gives you a firm price. There’s no call-out fee during business hours, no obligation, and the price is agreed before any work starts.
No call-out fee in business hours
You don’t pay for us to turn up and look during business hours.
Firm price agreed on site
Your plumber looks at the job and gives you a firm price before any work starts.
No obligation
If you decide not to go ahead, there’s nothing to pay during business hours.
Further work quoted first
If we find something else that needs fixing, we quote it and wait for your go-ahead before doing it.
Pay on completion
Cash, credit or debit card, or bank transfer with Osko, collected when the job is done.
After hours
After-hours call-out fees vary based on the day, time and location.
How to choose a backflow plumber
Whoever you call, these are the checks worth making before anyone works on your backflow device. Here’s how we measure up against each one.
Local plumbers, since 1985
Tap Doctor Plumbing & Gas has been doing plumbing and gas work since 1985. Our plumbers live and work in the areas they cover, so there’s usually someone close by, and our phones are answered 24/7.
Customers mention our plumbers by name in their reviews, from Mitch and Nathan to Chris and Charlie. Read Tap Doctor reviews →
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- Phone
- 1300-655-827, 24/7
Backflow prevention FAQs
What is a backflow prevention device?
A valve assembly fitted to a water service that only lets water flow one way, into the property. If pressure on the property side ever rises above mains pressure, or mains pressure drops, the device closes so used or contaminated water can’t be drawn or pushed back into the drinking water supply.
Does my property need a backflow device?
Most homes have a basic dual check valve at the water meter, which is not tested. Properties with a higher risk of contaminating the supply, such as businesses, medical practices, sites with fire services or irrigation that injects chemicals, and homes with a rainwater tank or bore connected to mains plumbing, usually need a testable device. Your water supplier or council sets what each property needs. If you’re not sure, call us on 1300-655-827.
How often does a backflow device need to be tested?
Testable devices generally need testing at least once every 12 months, and again when they are installed, repaired or moved. Your water supplier or council sets the exact requirement for your property.
What happens during a backflow test?
The plumber isolates the device, connects a test kit and checks that each check valve and relief valve opens, closes and holds pressure as it should. The water is off for a short time while the device is tested. We then explain the result and what, if anything, needs fixing.
What if my backflow device fails the test?
Most failures come down to worn seals, springs or a check valve that no longer seals. We tell you what failed and give you a firm price to service or repair it, then retest the device once the work is done. If the device is too far gone, we’ll explain the replacement options.
What’s the difference between an RPZ valve and a double check valve?
A reduced pressure zone device (RPZD) is used where the risk to the water supply is high and has a relief valve that dumps water if the check valves fail. A double check valve assembly is used for medium risk sites. Homes usually only need a non-testable dual check valve. The type you need depends on the hazard rating of the property.
Can you give me a price over the phone?
It depends on how many devices you have, what type they are, where they’re installed and whether anything needs repairing, so we don’t guess. A licensed plumber looks first and gives you a firm price before any work starts, with no call-out fee during business hours and no obligation.
Do you charge a call-out fee?
Not during business hours. You only pay for the work you agree to. After-hours call-out fees vary based on the day, time and location.
Are your plumbers licensed and insured?
Yes. Backflow testing and device work is done by licensed plumbers, and Tap Doctor is fully licensed and insured.
Need a backflow device tested?
Book online in under 2 minutes, or call us any time.