A leaking hot water system is usually a sign of internal tank failure or a faulty relief valve. If water is pooling around the base, treat it as an emergency. Property damage, and with electric units, a live electrical hazard. Kill the power and the water now, then call a licensed plumber.
Can I Still Shower if My Hot Water System is Leaking?
You can only safely shower if the leak is minor, it is coming from the pipework at the top of the unit, and the system is still heating normally. If water is coming from the bottom of the tank, or you have an electric unit with water anywhere near the wiring cover, do not use it. Don’t risk it. The risk of electrocution and flooding is too high.
The Shower Safety Checklist
Work through these four conditions in order, standing in front of the unit.
1. Is water actively spraying or steadily running?
If yes, stop. Do not shower. Go straight to the shut-off steps below.
2. Is it an electric unit with water leaking near or above the electrical cover?
If yes, stop. Do not shower and do not touch the unit. Isolate the circuit at the switchboard first.
3. Is the leak coming from the bottom casing of the tank itself?
If yes, stop. A tank breach means rupture is likely, and the volume of water that can come out of a failed cylinder will flood a laundry, garage or under-house space in minutes.
4. Is it a small drip from the TPR valve (the pipe running down the side) or a top connection?
If yes, you have a little breathing room. Take one quick shower if you need to, then shut the system down and book a plumber.
What to do right now, regardless of the result
- Move electrical appliances, boxes and anything valuable away from the unit and out of the path of the water.
- Put rubber-soled shoes on before you step anywhere near a pool of water.
- If the unit is inside, put down towels and open the space up so water is not soaking into skirting boards or carpet.
- Take a quick photo of the leak, and one of the sticker on the side of the unit with the model number and date on it. Your plumber can work out what you’ve got before he arrives.
Is It an Emergency? How to Safely Shut Off a Leaking Hot Water System
It’s an emergency the moment the water can flood the place, get into the structure, or reach anything electrical. Any leak from the body of the tank falls into that category. If you need someone out now, our emergency plumbers are available around the clock.
The 3-Step Isolation Protocol
Step 1: Kill the power or fuel supply first
Electric systems: Go to your switchboard and turn off the circuit breaker labelled “hot water” or “HWS”. If nothing is labelled, turn off the main switch.
Gas systems: Turn the control dial at the base of the unit to the OFF position, then turn the gas isolation valve on the supply pipe so the handle sits across the pipe rather than in line with it.
Heat pump and solar systems: Isolate at the switchboard the same way you would an electric unit. Solar systems have a booster circuit as well, so turn off anything labelled “solar boost”.
Step 2: Shut off the water supply
Find the cold water inlet at the top or upper side of the tank. There is usually an isolation valve or stop tap on that line. Turn it clockwise until it stops. If there is no valve at the unit, or it is seized, turn the water off at the main tap at the front boundary of the property instead.
Step 3: Relieve the pressure
Open a hot tap inside, kitchen sink is fine. If you’ve got a downstairs tap, use that one. This drains residual pressure out of the tank and stops it forcing more water out of the leak.
The mistake we see most often
Mistake: Turning off the water before turning off the power.
Why it matters: An electric element left switched on in a tank that is draining will burn itself out within minutes. What could have been a valve replacement turns into an element replacement on top of it. Always kill the power first.
How to check you have done it correctly: Go inside and turn on a hot tap. Water should run for a few seconds and then stop. If it keeps running, the cold supply is still feeding the tank and you have shut off the wrong valve.
Why is My Hot Water System Leaking From the Bottom?
It’s almost always sediment. Years of it building up inside the cylinder, rusting through the steel from the inside out. Once the internal lining is breached, water works its way through the insulation and pools on the floor.
Where the water is coming from, and what it means
| Where the water is coming from | What it means | Repair or replace |
|---|---|---|
| Pooling directly underneath the unit, no visible source | Internal tank rupture. The cylinder has failed. | Replace |
| Dripping from the drain valve at the very base | A loose or perished drain valve. The tank itself is usually fine. | Repair |
| Running down the side from the TPR valve pipe | The valve has worn out, or the system is over-pressurised. Some discharge during heating is normal, a constant stream is not. | Repair, and check the pressure |
| Wet around a fitting or pipe joint at the top | A failed connection or corroded fitting. | Repair, often quick |
The one that can’t be fixed: water coming through the casing itself, not from a pipe or valve. It can’t be patched or sealed. Once the steel’s gone, the tank’s gone. Anyone offering to repair it is selling you time, not a fix.
How Long Will a Hot Water System Last Once It Starts Leaking?
Once the tank itself goes, we usually see complete failure inside two or three days. If the leak is coming from a valve or a fitting, the system can go on for years once the part is replaced. Our hot water repair team can tell you which one you’re dealing with.
Repair or replace: how to work it out
| Check | Result | What to do |
|---|---|---|
| Age of the unit (from the sticker on the side) | Over 10 years old | Replace. On the coast most tanks give you 8 to 12 years, and a leak at that age means the tank has reached the end. |
| Age of the unit (from the sticker on the side) | Under 10 years old | Move to the next check. |
| Source of the leak | From the tank body or base | Replace. There is no repair for a breached cylinder. |
| Source of the leak | From a valve, fitting or connection | Repair. This is the cost-effective fix and the system has plenty of life left. |
Best suited to repair: Units under seven years old with a dripping TPR valve, a weeping drain valve, or a leak at a top connection.
Best suited to replacement: Units eight years or older leaking rusty water from the base, or any unit where the water coming out is discoloured. If that’s you, our guide on signs your hot water heater needs replacing covers what to look for.
Why the 10-year mark matters
The national average life of an electric storage tank is about 13 years. The warranty on the cylinder runs out at 10 to 12. That’s normal. Those numbers come from research cited in a report for the Australian Renewable Energy Agency, and the gap between them is the reason a leak at eleven years old is not a manufacturing fault. It’s the tank reaching the end of its working life.
The tanks we pull out around Mosman and Bondi tend to sit at the shorter end of that. Salt air and coastal water are harder on a cylinder. If yours is in that window and it has started leaking from the tank, replacement is almost always the right call.
Most people choose their hot water system in a panic
Around 830,000 hot water units are sold in Australia every year, and about 660,000 of them are replacing a system that has already failed. The same ARENA research found those replacements are usually like-for-like swaps, chosen for speed and convenience rather than because anyone compared the options. That’s the problem. Four out of five hot water systems in this country get chosen by someone standing in a wet laundry with no hot water.
If your system is over ten years old and still working, this is the argument for planning the replacement rather than waiting for it. A planned swap gives you time to look at running costs, rebates and whether a heat pump suits your property. An emergency one gives you about twenty minutes.
What to have ready when you call
Worth having sorted before you’re the one in the laundry. Give your plumber four things and you will get a considered recommendation instead of whatever is quickest:
- The age of the unit (from the sticker on the side).
- Whether it is gas, electric, heat pump or solar.
- The capacity in litres.
- Exactly where the water is coming from.
Talk to a Licensed Sydney Plumber About Your Leaking Hot Water System
North East Plumbing has been sorting out failed and leaking hot water systems across Sydney’s North Shore and Eastern Suburbs for years. James and Mitch bring 30 years of combined hands-on experience, and every job is quoted per job, never per hour, so you know the cost before we start.
- Lifetime Labour Guarantee on all work
- Fixed-price quoting with no hidden fees
- $90 onsite inspection fee, waived when you go ahead with the quote
We’re Master Plumbers NSW members, fully licensed and insured (Licence #364116C), 4.9 stars from more than 300 Google reviews, and available same-day or around the clock in an emergency. We put down shoe covers and drop sheets and clean up properly before we leave.
If your system is leaking right now, isolate the power and water using the steps above, then call James and Mitch on 02 7256 5711 for a fast quote.
