03 9888 2887
Published: August 2026 | Last updated: August 2026
Yes, a plumber fixes hot water, and when the water runs cold the cause is usually on a short list. Gas systems: a pilot light that’s gone out, a failed thermocouple, or a gas supply problem. Electric systems: a tripped breaker, a failed element, or a faulty thermostat. Any storage system: a leaking tank or a failed valve. A couple of these you can check safely yourself in two minutes; the rest are licensed work, and knowing which is which saves you either a call-out or a wasted afternoon in the garage.
Work through this before you ring anyone, including us.
The two-minute checks
- Is it just one tap? Kitchen hot, shower cold means the fault is at that fixture or its tempering arrangement, not the system.
- Gas: is the pilot on? Look through the sight glass. Out? Relight it following the panel instructions. If it lights and holds, you’re done, no charge, glad to help. If it won’t stay lit, the thermocouple has likely failed, which is a plumber’s part. And if the pilot is out and you can smell gas, don’t relight anything; our guide to pilot lights and gas leaks covers what to do instead.
- Electric: check the switchboard. A tripped breaker or blown off-peak fuse is the most common cause of a suddenly cold electric tank. Reset it once. If it trips again, stop. A circuit that keeps tripping is usually an element leaking to earth, and a third reset teaches you nothing a plumber doesn’t already know.
- Water at the base of the tank? From a valve or fitting, often repairable. Steady water from the tank body itself means the cylinder has corroded through, and no repair brings a split tank back.
- Has the street lost gas or power? It happens, and it’s worth thirty seconds before anything else.
Reading the symptoms
Hot water runs out fast. On electric tanks, one of the two elements has often died, so the tank half-heats and nobody can work out why showers got shorter. Sediment build-up, or a household that’s simply outgrown the tank, produces the same complaint.
Everything’s lukewarm. A drifting thermostat, or a tempering valve on its way out. The tempering valve caps delivery temperature for safety, and when it sticks, it drags the whole house down to tepid.
Hot, then cold, then hot. On continuous flow, that’s flow or ignition trouble. On storage, thermostat or valve.
Rusty hot water while the cold runs clear. The tank is corroding from the inside. Caught young, an anode change might arrest it; past 10 years, it’s the beginning of the end, and our lifespan guide covers the replacement triggers.
No hot water and water everywhere. Main off at the meter, then treat it as urgent. A burst tank dumps its contents plus mains flow behind it, and our emergency plumbers attend 7 days.
Who do I call to fix a hot water system?
The plumber, whatever the fuel. Hot water systems live on the water supply, so diagnosis and most repairs are licensed plumbing work; gas faults are gasfitting, a plumbing class; and where an electric fault needs element or switchboard wiring, a licensed electrician takes that piece. Because O’Shea Plumbing and O’Shea Electrical sit in the same family group, a fault that turns out to be electrical doesn’t mean a second company and a second wait; it means the next van. Most no-hot-water calls end the same day, with common parts for the major brands already on board.
Repair or replace, and the 2027 wrinkle
Under about 8 years old with a failed valve, element, thermocouple or thermostat: repair it. Past 10, or leaking from the cylinder: replace it, because repairs at that age buy months at full price. Between those markers it’s a judgement call, and we’ll make it with you, not for you; sometimes the honest answer is “this repair gets you through winter, start planning.”
Gas owners have one more date in the mix. From 1 March 2027, Victorian rules require an end-of-life gas hot water system in an existing home to be replaced with an efficient electric alternative such as a heat pump. Repairs stay legal, but a gas tank that dies after that date can’t be replaced with gas. If yours is already limping, replacing it on your schedule before then, gas one last time or a rebate-backed heat pump now, beats an unplanned changeover in the coldest week of 2027.
Frequently asked questions
Does a plumber fix hot water? Yes. Hot water diagnosis and repair is core plumbing work, with gas faults under the gasfitting licence and electrical circuit work brought in from a licensed electrician when the fix needs it.
Can a plumber fix no hot water? Usually in a single visit. Pilots, thermocouples, valves, thermostats, elements and fitting leaks are all standard repairs with parts carried on the van.
Who do I call to fix a hot water system? Start with the plumber. We work out whether the fault is water, gas or electrical and coordinate the rest either way.
Why is my hot water not working? Most often: pilot out or thermocouple gone (gas), breaker tripped or element failed (electric), or a tank or valve leak. The two-minute checks above sort the safe DIY cases from the rest.
Cold shower this morning? Call O’Shea Plumbing on 03 9888 2887 or book a repair. Fixed price before we start, 7 days across Melbourne.
