A backflow prevention device stops water that has left the mains from finding its way back into it. It matters most where the water on the property side is not drinking water — irrigation running through fertiliser injectors, a commercial kitchen, a wash bay, a dental surgery, a fire service, a cooling tower.
The part that catches people out is that these devices are not fit-and-forget. Testable devices have to be tested when installed and then at least once a year, by someone accredited to do it, with the result submitted to the water authority. The first most owners hear about it is a letter, or a request from an incoming tenant's compliance check.
What we handle
- Annual testing of testable backflow prevention devices, with the paperwork lodged
- Testing on installation, and again after any repair
- Servicing, rebuild kits and replacement of failed devices
- New device installation where a hazard rating requires one
- Working out which device a property actually needs, and where it goes
- Reminders, so the next one is a booking rather than a letter
Worth knowing
It is an annual obligation, not a one-off
A testable device has to be tested at least every twelve months and the result recorded with the water authority. Missing it is a compliance problem rather than a plumbing one, and it tends to surface at the worst moment — a lease renewal, a sale, an audit, or an insurance question after something else has gone wrong.
Not every property needs one
It comes down to the hazard rating of what is connected on your side of the meter. Most ordinary houses do not have a testable device; a house with a bore, an irrigation system with chemical injection, or a pool auto-fill might. If you are not sure whether you have one, we can look.
Test failures are usually repairable
A device that fails a test has almost always got a perished seat or spring rather than a terminal fault. A rebuild kit and a retest is the normal outcome, and it is a great deal cheaper than replacement.
Common questions
How often does a backflow device have to be tested?
At least once every twelve months for a testable device, and again whenever it is installed, relocated or repaired. The test has to be carried out by someone accredited for it and the result submitted to the water authority — it is not a self-certification.
How do I know if I have a backflow device?
It is usually a brass assembly with two isolating valves and small test cocks, sitting near the meter or on the line feeding whatever the hazard is — the irrigation, the kitchen, the wash bay. If there is a tag on it with a date, that is the last test. Send us a photo and we will tell you what it is.
What happens if it fails the test?
It gets repaired or replaced and then retested, and the passing result is what gets lodged. In most cases it is a rebuild kit fitted on the same visit. We tell you which one you are looking at before doing the work.
Do you handle the paperwork?
Yes. The submission is part of the job, not an extra — a test that is not lodged has not really been done as far as anyone checking is concerned.