Make it safe first
Power or gas off
For an electric or heat pump unit, switch it off at the switchboard. For gas, turn off the unit's gas if you can do it safely.
Water off
Close the cold water valve on the pipe feeding the unit.
Keep hands clear
Stay away from the relief valve outlet and any open drain fitting: the water coming out can scald.
Protect the floor
Move anything that can get wet and, if the unit is indoors, put towels down.
Where the water is coming from
| What it usually means | Repair or replace | |
|---|---|---|
| Relief valve drain, a few drips while heating | The valve letting out pressure as the water expands | Often normal; mention it at the next service |
| Relief valve drain, a constant flow | A worn valve, or pressure or temperature running too high | Repair, and find the cause |
| A pipe joint or valve above the tank | A loose or worn fitting | Repair |
| Under a heat pump | Condensate from the heat pump, which is expected | Check it drains away properly |
| The tank body or base | The inner tank has corroded through | Replace |
What a plumber will do
A plumber will trace the water to its source, check the relief valve, and test the pressure coming into the unit. If the tank is sound, they replace the valve or remake the joint. If it isn't, they drain and disconnect it, and talk you through the replacement.
Looking after the relief valve
Water Corporation in Western Australia suggests releasing the pressure valves for a few seconds each month to prevent scale building up in your hot water system.
Read your unit's instructions first, stand clear of the outlet, and call a plumber if the valve won't close properly afterwards. Never plug or cap a dripping relief valve: it's a safety device.
If the tank has gone
A leaking tank can't be patched. Replacing it brings the rules for a new unit into play: in some states a tempering valve, and in Victoria the 2027 gas rule if the old unit ran on gas. Check current rules.
Planning to use Victoria's Solar Homes rebate? Solar Victoria says that if your system breaks down or is unsafe, you don't have to wait for it to confirm you're eligible before the replacement goes in. See Victoria's rebate and discounts.
Choosing the new one: hot water replacement.
Paperwork after the fix
In Western Australia, which paperwork you get depends on the fix. A repair to the water heater counts as minor work and only needs a record. A new heater is not minor work, so expect a certificate of compliance within five working days.
Wherever you are, ask for the plumber's licence number before work starts: our licence guide shows how to check it.
What you can do while you wait
You can
- Turn off the power or gas, and the cold water to the unit.
- Photograph where the water is coming from.
- Note the brand, model and install date from the label.
- Watch whether a relief valve drip stops once the tank has finished heating.
Leave to a licensed plumber
- Replacing the relief valve or other valves.
- Remaking leaking joints.
- Draining and removing a failed tank.
- Finding out why a valve keeps releasing, if pressure is the cause.
Red flags when a leak is diagnosed
- You're told the tank is leaking, but shown only a dripping valve.
- Pressure to install a new system that day without hearing the options.
- A relief valve plugged or capped to stop the drip.
- No mention of the paperwork your state requires.
What we would do
Turn it off, then look before you worry. A drip from the relief valve drain or a fitting is usually a quick repair. Water from the tank body isn't, and parts won't save it. Get a hot water specialist to confirm which you have, and if it's the tank, use the time while the water's off to choose the replacement properly.