Do this first
Keep away from wet electrics
If water has reached the switchboard, a power point or any wiring, don't touch it. Stay out of the water and ring an electrician.
Turn the cylinder off
Switch the hot water circuit off at the switchboard. On a gas heater, turn the gas off at the heater's isolation valve or at the meter or bottle.
Shut off the water
Close the cold water valve that feeds the cylinder. If you can't find it, turn the water off at the toby, the shut-off near your front boundary.
Protect the house
Put down towels or a bucket, move anything valuable, and photograph the leak and the damage for your insurer.
Then book the repair
Before you ring, have a look at where the water seems to start. It helps the tradie bring the right parts.
Where is the water coming from?
| What it can mean | Usually | |
|---|---|---|
| A pipe joint or fitting | A loose, worn or corroded connection | A repair |
| A valve or the pipe it drains into | A valve that needs servicing or replacing | A repair |
| The tank body or a seam | The inner tank has failed | A replacement |
| A full safe tray | A leak somewhere above it, or a blocked tray drain | A plumber needs to look |
| A damp ceiling or wall nearby | A leak that has been going for a while | Book soon |
Why a slow leak still matters
Rheem's owner's guide makes the point that even a small hot water leak wastes a surprisingly large amount of water, and the energy that heated it. A drip into a safe tray can also be hiding a bigger problem.
The Building Code expects water systems to be installed so leaks are unlikely, and so the system can be isolated for maintenance. Rheem's mains pressure guide calls for a properly drained safe tray wherever a leak could damage furniture, carpets or the building.
Use an authorised tradie for the repair and keep their invoice. PGDB warns that a homeowner's insurance may be void if unlicensed work goes wrong.
Urgent work and consent
Most leaking cylinders end in a repair, which Schedule 1 clause 36 exempts from consent, or a replacement under clause 38. Both exemptions depend on an authorised person doing the work.
The Building Act also lets urgent work go ahead without a consent when one can't practicably be obtained first, to protect life or health or to prevent serious damage. If work that would normally need a consent is done that way, the owner must apply for a certificate of acceptance as soon as practicable. Our hot water cylinders hub covers the rest of the rules.
While you wait
You can
- Turn off the power or gas, and the water to the cylinder.
- Mop up, lift rugs and protect flooring.
- Photograph the leak, the safe tray and the cylinder's label.
- Work out whether it's dripping from a valve's drain pipe or from the cylinder.
Leave to an authorised tradie
- Opening the cylinder casing or covers.
- Replacing valves, fittings or sections of pipe.
- Draining and replacing a failed cylinder.
- Reconnecting the gas (an authorised gasfitter) or the power (an electrician).
Red flags after a leak
- Advice to cap a dripping valve and carry on using the cylinder.
- A replacement price before anyone has found where the water comes from.
- No practising licence shown when the tradie arrives.
- Someone offering to reconnect the gas who isn't an authorised gasfitter.
What we would do
Turn it off first, then find the source. A drip from a fitting or valve is often a straightforward fix, while water from the tank itself means planning a new cylinder. Ring someone who handles cylinder leaks regularly rather than a general handyman, because the valves and safety devices on a cylinder are restricted plumbing work.