If you live in Kogarah or nearby suburbs in St. George, your hot water system probably plays a bigger role in your daily life than you realise. From those early-morning showers that help you wake up to the hot water you use for cooking, cleaning, and laundry, your hot water storage tank works around the clock. But when that tank starts leaking, even small leaking storage tank signs can turn into a serious problems if you don’t address it quickly.
We’ve worked with countless homeowners in Kogarah who noticed warning signs but put them off because “it’s probably nothing.” Unfortunately, most of them called us when the leak had already caused water damage, mould growth, or a total system failure. Acting fast can save you from expensive repairs, protect your home, and keep your hot water flowing.
Common Signs of a Leaking Hot Water Storage Tank
1. Water pooling around the base of the tank
If you see even a small puddle forming under or around your hot water tank, don’t assume it’s harmless. Water pooling is often the earliest and most obvious sign that your tank is leaking. This water could be coming from a crack in the tank, a faulty valve, or a loose connection. Ignoring it allows moisture to seep into floors and walls, leading to hidden damage that’s costly to repair.
2. Unexplained spikes in water bills
If your water usage hasn’t changed but your bill has jumped, a leak in your hot water tank could be quietly wasting litres every day. Because the leak may be slow and hidden, you might not see the water loss — but you’ll feel it in your wallet.
3. Reduced hot water supply or temperature fluctuations
When your storage tank leaks, it can’t hold the same amount of water or maintain consistent pressure. That means you’ll notice shorter showers, inconsistent water temperatures, or the need to wait longer for hot water to return. These changes can happen gradually, making them easy to overlook.
4. Visible rust or corrosion on the tank surface
Rust or corrosion on the outside of your tank is often a clue that the inside is also deteriorating. Corrosion eats away at the metal, weakening the tank’s structure and making it more prone to leaks. If you can see it on the surface, it’s time to have the tank inspected before it bursts.
5. Dampness or mould growth nearby
A damp patch on the floor, wall, or skirting board near your tank is a sign that moisture is escaping. Mould thrives in these damp conditions, and once it spreads, it can cause respiratory issues and trigger allergies. Eliminating mould after the fact is far more expensive than stopping the leak early.
6. Dripping sounds when no taps are on
If you hear water dripping, hissing, or running when no one in your home is using water, the sound may be coming from inside the tank or nearby pipes. This is often a hidden leak that’s wasting water and creating moisture damage in places you can’t see.
7. Discoloured hot water
When rust or sediment builds up inside your tank, it can turn your water a brownish or reddish colour. Not only is this unpleasant, but it’s also a sign that your tank’s lining or anode rod is breaking down. Left unchecked, the corrosion will eventually create holes in the tank.
Pro-Tip: Place a dry paper towel or piece of cardboard under the suspected leak overnight. If it’s damp the next morning, you’ve confirmed the problem without needing to dismantle anything.
Causes of Leakage in Hot Water Storage Tanks
Age and wear of the tank or its components
Most tanks last 8–12 years. As they age, the constant heating and cooling cycles weaken the metal and seals, making leaks more likely.
Pressure relief valve malfunction
If the pressure relief valve fails, it might release more water than it should, creating a constant drip or puddle near the tank.
Corroded pipes or fittings
The pipes and fittings connected to your tank are just as vulnerable to corrosion as the tank itself. When these parts rust or weaken, they can develop leaks that mimic tank failure.
Faulty plumbing connections
Even a small shift in pipe alignment or a loose joint can let water escape. These issues often start small but worsen over time.
Physical damage to the tank
A dent or impact from moving the tank or accidental bumps can create weak spots in the structure, leading to future leaks.
Pro-Tip: Book an annual plumbing check-up to catch small issues before they turn into expensive repairs or full tank replacements.
Risks of Ignoring Leaks
Water damage to your property can happen fast. Even small leaks can cause swelling in floorboards, stains on ceilings, and peeling paint. Mould growth is another major risk — it can take hold within 24–48 hours in damp areas and may require costly remediation. On top of that, a leaking tank uses more energy to maintain water temperature, driving your power bills up. Worst case? The tank fails suddenly, flooding the area and leaving you without hot water.
We once worked with a Kogarah family who noticed water pooling near their laundry area but thought it was just from washing machine splashes. By the time they called us, the leak had warped their floor, spread mould behind the skirting boards, and damaged nearby cabinetry.
What to Do When You Suspect a Leak
Shut off the water supply to the tank immediately.
This stops further water loss and reduces the risk of damage.
Turn off the power or gas supply.
This keeps the system safe and prevents damage to heating elements or gas components.
Call a licensed plumber right away.
Professional assessment ensures the leak is fixed properly the first time.
FAQs About Leaking Storage Tank Signs
How can you tell if your underground oil tank is leaking?
Typical signs include unusual smells around the tank area, dead vegetation above or near the tank, oily residues in the soil, and unexplained drops in oil levels.
What is not a symptom of a failing underground storage tank?
Normal water usage changes or minor temperature fluctuations in household water are not usually linked to underground tank failure.
How to tell if septic is leaking?
Watch for strong, unpleasant odours, unusually soggy or wet patches in your yard, slow-draining fixtures, and sewage backups.
Why is my water tank dripping from the bottom?
This could be due to corrosion inside the tank, faulty valves, or cracks forming at the base. It’s a sign the tank needs professional attention as soon as possible.
How to shut off a leaking water tank?
Find and turn off the main water shutoff valve connected to the tank. If it’s an electric or gas unit, also switch off the power or gas supply before calling a licensed plumber.
What if I need to get services for different leaking storage tank signs?
No matter how simple or complicated the problem is, All Needs Plumbing has got you covered. We repair all kinds of hot water leaks, from faulty valves to full tank replacements, so you won’t have to go without hot water when you need it most.
We offer a $0 callout fee, 24/7 same-day service, a 15% seniors’ discount, and $150 off hot water systems. Let’s get your hot water system back in perfect working order — contact All Needs Plumbing today and we’ll be at your Kogarah home before you know it.
