When to call a plumber
- You are putting in a new tank and want it connected to the roof and the house.
- The tank is in, but the toilet or laundry still runs on mains water.
- The overflow is spilling against the house or into a neighbour's yard.
- The tank is leaking from a fitting or the outlet.
- The pump runs when nothing is on, or will not start: see tank pumps.
- The house does not switch back to mains water when the tank is empty.
What a plumber will do
A plumber will connect the downpipes to the tank inlet through a leaf screen, and usually a first flush diverter, which sends the first dirty water off the roof away from the tank. They will connect the overflow so it runs to the stormwater system instead of pooling against your walls; see stormwater drains.
If the tank will supply the house, the plumber will fit a pump and run a separate pipe to the toilets, laundry or garden. A changeover device switches the house to mains water when the tank runs low. The tank pipes are labelled and kept apart from the drinking water pipes, and backflow protection stops tank water being pushed back into the mains.
Where the downpipes are a long way from the tank, the plumber may run them underground and up into the tank inlet. Ask how that pipe will be drained and kept clear.
What changes the job
The size and position of the tank decide the base it needs and how many downpipes can reach it. A tank that only waters the garden needs far less pipework than one plumbed into the toilet and laundry. Access matters: a tank down a narrow side path, or a slab to be poured first, adds time. The pump also needs a power point, which is an electrician's job if there is none nearby.
Ask the plumber whether your council or water company needs anything from you before the tank goes in, because requirements differ around Australia.
Looking after a tank yourself
You can
- Keep gutters, leaf screens and the first flush diverter clear, especially after storms and in autumn.
- Check the insect screens on the inlet and overflow are intact.
- Watch the level and listen for the pump: running when no tap is on means a leak somewhere.
- In Queensland, the QBCC guide treats irrigation fed from downstream of a tap, isolating valve or backflow device as unregulated work.
- For anything connected to the house plumbing, check what you can do yourself first; most states have no homeowner list we could confirm.
Leave to a licensed plumber
- Connecting the tank to the toilet, laundry or any indoor fixture.
- The mains switching device and backflow protection.
- Overflow and stormwater connections.
- Pump installation; the electrician handles any new power point.
The rules that touch tank plumbing
Treat connecting a tank to the house plumbing as work for a licensed plumber. NSW requires a contractor licence for plumbing at any value. In Western Australia, installing or replacing a backflow device is not minor work, so the plumber owes you a certificate of compliance within 5 working days of finishing. In South Australia, backflow device work is among the jobs that need an electronic certificate of compliance, given to you within 7 days.
Roof water is a plumbing category of its own in Tasmania, where the regulations list roof (stormwater) work alongside water, sanitary and drainage work. Our compliance certificate guide covers each state's paperwork.
Questions to ask the plumber
- How will the house switch to mains water when the tank runs out?
- What backflow protection will you fit, and will it need testing?
- Where will the overflow go?
- Which fixtures will run on tank water, and how will those pipes be marked?
- Will I get a certificate of compliance for this work?
What we would do
Decide what the tank is for before choosing it. For the garden only, keep it simple and put it close to a downpipe. For the toilet and laundry, budget for the pump and the mains switch, and have it plumbed in by someone who does tank connections regularly: a badly set up switch leaves you without water, and a missing backflow device puts the mains at risk. Ask for the certificate where your state requires one, and keep it with your house papers.