Hot Water Leaking? What the Leak Location Tells You
A leaking hot water system is one fault where where it's leaking from tells you almost everything. A drip from a valve is a cheap fix; water from the base of the tank usually isn't. Here's how to read it.
What the leak location tells you
With a leak, the location is the diagnosis. Hot water leaking from the relief valve (a steady drip from the TPR or expansion valve) is common and usually a cheap valve replacement. Hot water leaking from the top often means a fitting, inlet/outlet connection or valve — also repairable. But hot water leaking from the bottom of the tank, pooling underneath, usually means the steel tank has corroded through — and a failed tank can't be patched reliably, so that's a replacement.
Because a leak can be anything from a $-simple valve to a dead tank, the first job is to identify where it's coming from — don't ignore it, as a slow leak can become a sudden failure.
What's probably causing it
Ranked by how often we see it — tell us which sounds like yours and we'll come prepared.
Relief valve dripping (TPR / expansion)
A steady drip from the temperature-pressure relief valve is common — often a worn valve or a pressure issue, and usually a cheap replacement.
Leaking from the top
Water at the top of the unit points to inlet/outlet fittings, the cold-water connection or a valve — generally repairable.
Leaking from the bottom (tank failure)
Water pooling under the tank usually means the steel tank has corroded through. A failed tank can't be reliably patched — it's a replacement.
Tempering or isolation valve
A weeping tempering or isolation valve can look like a tank leak but is a straightforward valve fix.
Pressure / expansion issue
Too-high incoming pressure can push water out of the relief valve — fixing the pressure (a PLV) stops the drip.
Valve drip = cheap fix · pooling under the tank = usually a same/next-day replacement.
What's safe to check — and what isn't
A few checks are safe for anyone; the rest is a licensed gas or electrical job.
What's safe to check yourself
- Where exactly is the water coming from — valve, top, or base?
- Is it a steady drip or a pool under the tank?
- Turn off the water isolation to the unit if it's flowing badly
- Note the location to tell us — it speeds the diagnosis
A pool under the tank usually means the tank itself has failed — don't delay the call.
When to call a licensed pro
- Water pooling under the tank
- A relief valve that won't stop dripping
- Any leak at fittings, valves or connections
- Hot water and electricity/gas near a leak
Valve and tank work is a licensed job — and water near power needs care.
How we fix a leaking hot water system
The licensed repair, and the fastest path back to hot water.
We identify exactly where it's leaking from and quote the fix. A dripping relief or tempering valve is a quick, affordable replacement; a fitting leak is repairable. If water is coming from the base of the tank, we'll be straight with you — the tank has failed, and the right fix is a replacement, often same or next day so you're not without hot water.
If it's specifically the relief valve, our TPR valve guide explains why it drips and when it needs replacing.
See also: book a repair · about the TPR valve · replace it — the tank has failed
Hot Water Leaking? What the Leak Location Tells You questions, answered
If yours isn't here, call — the line's attended 24 hours.
Why is my hot water system leaking from the bottom?
Is a leaking relief valve serious?
My hot water is leaking from the top — is that fixable?
Can you repair a leaking hot water tank?
Should I turn the water off if it's leaking?
How fast can you fix a leak?
Tell us what's happening — we'll fix it
Call the 24-hour line with your suburb and the symptom, or request a quote. We prioritise no-hot-water call-outs and come prepared with the likely parts.