No hot water is one of a small number of faults, and you can narrow it down in about five minutes. Two of the six checks below you can safely do yourself. The other four are licensed plumbing or gasfitting work in Victoria, which means the useful thing you can do is identify which one you are looking at, so that whoever comes out arrives with the right part.
Work through them in order. The first two cover most calls.
Water Pooling Under the Unit, or a Smell of Gas?
Stop here. If water is pooling, isolate the cold supply at the unit and turn off the power or gas. If you can smell gas, do not touch any switch, open the doors and windows, get everyone outside, and call the gas emergency line before you call anyone else. Neither of those is a troubleshooting situation.
First: Did It Run Out, or Is It Broken?
These feel identical in the shower, and they are completely different problems.
A system that has run out delivered hot water, then went cold partway through, and recovers by itself after an hour or two. That is a capacity or recovery issue: sediment in the tank, a failing element, or simply more demand than the unit was sized for. Melbourne winter makes it worse, because incoming mains water is colder and the unit has to work harder to reach the same temperature.
A system that is broken never produces hot water at all, and does not recover on its own. That is what the rest of this page is about. If yours ran out rather than failed, the checks below will not find anything wrong.
Check 1: The Pilot Light (Gas Storage Units)
If you have a gas storage system, this is the most common cause by a wide margin, and the defining Melbourne winter callout.
There is a small viewing window near the base of the unit. Look for a flame. If there is none, the pilot has gone out,t and the burner cannot fire, so the tank slowly goes cold over several hours. That is why so many people discover it in the morning.
Most units carry relighting instructions on a label on the casing, and following the manufacturer’s own procedure is reasonable. What matters more is what happens next. If it lights and then goes out again, stop relighting it. A pilot that will not stay lit usually means a failing thermocouple, a gas supply problem or a draught issue, and repeatedly relighting a unit that keeps dropping out is not a fix. Gas appliance work in Victoria is licensed gasfitting work.
Check 2: Power and the Off-Peak Tariff
The electric equivalent, and the other check worth doing yourself.
Go to the switchboard and look for a breaker labelled hot water. If it has tripped, reset it once. If it trips again immediately, leave it off and call someone. A breaker that will not hold is reporting a fault in the element or the wiring, not a nuisance trip.
Then consider the tariff. Many Melbourne homes run their hot water on a controlled or off-peak circuit that only heats overnight. If the tank was emptied during the day, it may simply not reheat until the small hours. The tell is a household where hot water reliably returns by morning and disappears by evening. That is not a fault at all;l, it is a unit that is undersized for how the house actually uses water.
Where the DIY Stops, and Why
Checks 1 and 2 are the end of what a homeowner should be doing. Everything below involves a pressurised vessel of scalding water, 240 volt wiring, or gas controls, and in Victoria, work on a hot water system is licensed plumbing and, where gas is involved, licensed gasfitting. This is not caution for its own sake. A thermostat fitted when the real fault was a scaled element wastes the part and leaves the fault in place, so the diagnosis matters as much as the repair.
Check 3: An Isolation Valve That Got Turned Off
Worth ruling out, because it costs nothing and it does happen. If anyone has worked on the plumbing recently- a tradesperson, a renovation, a solar install or a meter replacement- the cold supply isolation valve at the unit can be left partly or fully closed. No cold water entering means no hot water leaving.
The giveaway is timing. If hot water stopped within a day or two of someone working on the house, mention that when you call. It reframes the whole diagnosis.
Check 4: An Error Code (Continuous Flow)
Continuous flow units do not store hot water. They heat it on demand, and when something is wrong, they stop and display a code, either on the unit itself or on a bathroom or kitchen controller.
Write the code down before you call. Codes aremanufacturer-specific,c and they point to very different faults: ignition failure, a flame sensing problem, overheating, or water flow below the minimum the unit needs to fire. Reading the code out on the phone often tells us whether this is a part we should bring with us, which can be the difference between one visit and two.
Check 5: The Relief Valve Discharging
Every storage tank has a temperature and pressure relief valve with a discharge pipe running to a drain point. Releasing a small amount of water during a heating cycle is the valve doing its job.
A constant stream is not. A relief valve stuck open drains heated water continuously, so the burner or element runs without the tank ever holding temperature, which presents as weak hot water or none at all. It also points to either a failing valve or mains pressure higher than the system is rated for. Both are fixable, and neither means a new tank.
Check 6: The Unit Is Leaking
Water around the base changes the situation from an inconvenience to something that needs attention today.
Where it is coming from decides whether it can be repaired. A leak at a fitting, a valve or the drain tap is usually a straightforward repair. Water weeping from the body of the tank itself is not, because the steel has corroded through from the inside and a pressurised vessel cannot be patched safely. Our guide to a hot water system leaking from the bottom explains how to tell the two apart, and what to do in the first five minutes.
Worked Through the List and Still Cold?
Tell us three things: whether it is gas or electric, roughly how old the unit is, and what you found on the list above. Those three answers usually tell us whether this is a repair or a replacement before we leave the depot, and let us arrive with the right part. Available 24/7 across Melbourne, with no call-out fee, and we quote before we start.
What Each Check Actually Points At
| Check | System Type | Who Can Do It |
|---|---|---|
| 1. Pilot light out | Gas storage | You, once. If it will not stay lit, a licensed gasfitter |
| 2. Breaker or off-peak tariff | Electric | You, once. If it trips again, leave it off and call |
| 3. Isolation valve closed | Any | Licensed plumber |
| 4. Error code showing | Continuous flow | Read the code yourself, thencall a licensed plumber or gasfitter |
| 5. Relief valve discharging | Storage, gas or electric | Licensed plumber |
| 6. Unit leaking | Storage | Licensed plumber, same day if water is pooling |
A system that fails in a Melbourne July rarely comes back on its own, and the units that fail are usually the ones that were already marginal. Cold inlet water means longer burn and heating cycles, which is exactly the load that finds a tired thermostat or a scaled element. If yours has been getting slower for a season, it has been telling you something.
Frequently Asked Questions
Why do I suddenly have no hot water?
On a gas storage unit, most often the pilot light has gone out, so the tank cooled overnight. On electric, it’s a tripped breaker or a controlled tariff that has not reheated yet. Beyond those two, the usual causes are a failed thermostat or element, a relief valve stuck open, or a tank that has reached the end of its life. Work through the six checks above, and the answer is usually in the first two.
Can I relight the pilot light myself?
Following the manufacturer’s instructions on the unit is reasonable once. If it lights and stays lit, that was the fault. If it goes out again, stop. A pilot that will not hold points to a failing thermocouple, a gas supply issue or a draught problem, and in Victoria gas appliance work is licensed gasfitting. Repeated relighting does not fix any of those.
Is no hot water an emergency?
Not usually, on its own. It becomes one if water is pooling around the unit, if you can smell gas, or if there is someone in the house who genuinely cannot go without, such as a young baby or an elderly or unwell person. Otherwise it is urgent rather than dangerous, and it should still be looked at quickly because a partial fault tends to become a total one.
Should I repair it or replace it?
Age and the nature of the fault decide it. A unit under roughly eight years old with a single failed component is usually worth repairing. One past ten years, leaking from the tank body, or producing rusty water is generally at the end of its service life, and putting a new part into a corroded tank buys months rather than years. If it is a replacement, a heat pump may be worth considering, and there is a Victorian rule about replacing end-of-life gas systems that is worth knowing before you decide.
What does a hot water repair cost?
It depends on which fault you have, whether the part is a thermostat, an element, a valve or a thermocouple, whether the system is gas or electric, and whether the unit is worth repairing at all. That is why the three questions we ask on the phone are system type, age and what you found on the checklist. We quote a fixed price for the agreed work before we start, and there is no call-out fee.
My hot water works but only lasts a few minutes. Is that the same problem?
No, and it is worth separating. If you get hot water that runs out quickly, the system is heating but cannot deliver enough, which points to sediment in the tank, a failing element or a unit undersized for the household. Nothing on the six-point list will find it, because nothing has actually failed. A system that keeps cutting out mid-cycle is different again, and our guide to a hot water system that overheats and shuts down covers that one.
Cold Shower and Out of Ideas? We’ll Sort It.
Tell us your suburb and what you are seeing, whether that is an error code, a pilot that will not light, water on the floor, or nothing at all. We will tell you honestly whether it is a repair or a replacement rather than selling you a tank you do not need. Over ten years of experience with Melbourne hot water systems, available 24/7, no call-out fee. See our hot water repairs and hot water system replacement services.
