Rainwater tank maintenance checklist
Ten minutes of checking now and then saves a dirty tank and a burnt-out pump.
Water tank maintenance comes down to keeping the dirt out and checking the parts that move. Most of it is a quick look from the outside. Do it a few times a year and after big storms.
Every few months
Check the gutters and leaf screens for debris. A blocked gutter overflows onto the wall instead of feeding the tank. Look at the inlet screen and the overflow screen for holes or clogging.
Empty the first flush diverter if yours is not self draining. Glance at the lid as well. It should sit tight, with no gaps for insects.
Once a year
Check for mosquito larvae by looking at the water surface from the inlet. Larvae mean a screen has failed. Look at the tank walls and base for cracks, rust or a damp patch.
Test the float valve if you have a mains top-up. Watch that it shuts off properly. A stuck valve wastes mains water and can hide a leak.
Every few years
Plan for a tank clean to remove sludge. Do it sooner if trees overhang the roof. Clean or replace the pump suction filter when flow drops. Keep an eye on the pump for noise or short cycling.
| When | Check | Why it matters |
|---|---|---|
| Every few months | Gutters, leaf screens, inlet and overflow screens | Stops debris and pests getting in |
| After a big storm | Overflow flow and screens | Heavy rain can block them |
| Once a year | Water surface, tank walls, float valve | Catches larvae, cracks and stuck valves |
| Every few years | Sludge, pump filter, pump condition | Protects water quality and the pump |
Do not rely on maintenance to make water safe
A tidy tank is a cleaner tank. It is not a tested one. Bird droppings, roof materials and dust all affect the water, and you cannot see most of it. If anyone drinks it, test it.
Warning signs between your regular checks
The schedule above keeps you ahead of most problems. These signs mean you should check sooner.
| Sign | What it often means | First move |
|---|---|---|
| Cloudy water or a musty smell | Sludge or organic matter on the floor | Check the screens, then plan a clean |
| Mosquito larvae on the surface | A screen has failed | Repair or replace the screen |
| Pump starts and stops often | A leak, or a vessel that has lost its air charge | Check taps and toilet cisterns |
| Overflowing on dry days | The float valve is not closing | Test the valve and call a licensed plumber |
| Gutters spilling over the wall | Blocked gutter or leaf screen | Clear the debris from a safe position |
| Damp patch on the tank base | A leak or a poor overflow path | Dry it, wait a day and trace the highest wet point |
Keep this list near the switchboard. A short note of dates and findings helps a plumber later.
Jobs for you, and jobs for a licensed trade
Most tank upkeep is safe to do from the ground. These are the limits.
| Job | Who does it |
|---|---|
| Clearing gutters and leaf screens from a safe position | You |
| Checking the inlet and overflow screens | You |
| Emptying a first flush diverter | You |
| Looking over the walls and base from outside | You |
| Cleaning the pump suction filter | You, if the pump manual allows it |
| Entering the tank | Never. It is a confined space; use a trained tank cleaner |
| Cutting into pipework, roof drainage or the house connection | A licensed plumber |
| Pump wiring | A licensed electrician |
Rules differ by state and territory, so check with your regulator. For the sludge side, see how to clean a rainwater tank.
Frequently asked questions
How often should a rainwater tank be maintained?
Check the screens and gutters every few months and after storms. Do a fuller check once a year. Plan a clean every few years.
What should I check on a rainwater tank?
Gutters, leaf screens, the inlet and overflow screens, the lid, the float valve, the first flush diverter and the pump filter.
Does maintenance make tank water safe to drink?
No. Maintenance keeps the tank clean, but only testing by a NATA accredited laboratory tells you about drinking water quality.
Can I do tank maintenance myself?
Routine checks and clearing screens, yes. Pipework, pump wiring and house connections need licensed trades.
Sources
What this page explains is based on these official sources. If you check one and it does not match what you read here, send it to us and the article gets corrected.
- NHMRC. Australian Drinking Water Guidelines
- Australian Building Codes Board. National Construction Code — Volume Three (Plumbing Code of Australia)