The short answer
Start with the simple stuff. On gas, check the pilot light is lit and the gas is on. On electric, check the hot water circuit breaker and any off-peak timer. On solar, check the booster is switched on, especially in winter. On continuous flow, check it has power and look for an error code on the controller. If the tank is leaking from the bottom, it has usually reached the end of its life: turn off the cold water to the unit and the gas or power, then call McDermott Plumbing on (08) 6187 3999 or text 0406 882 648.
Quick checks by system type
Only go as far as the manufacturer’s instructions on the unit allow. Anything inside the gas controls or the electrical cover is a job for a licensed gas fitter or electrician.
- Gas storage: is the pilot light lit? If it keeps going out, it’s often a worn thermocouple or wind blowing it out on an outdoor unit. Are other gas appliances working? Is the gas meter valve on?
- Electric storage: has the hot water circuit breaker tripped? If you’re on an off-peak or timer arrangement, it may simply have run out of heated water for the day. A breaker that trips again straight away usually means a failed element or thermostat.
- Continuous flow (instantaneous) gas: it needs power as well as gas. Check the power point and look for an error code on the controller. Low flow at the tap can stop it firing, so try a different tap turned right up.
- Solar: in winter most solar systems rely on the gas or electric booster. Make sure the booster is switched on. A system that’s only warm on sunny days may have a booster fault.
- Heat pump: check the power and the unit’s display for a fault code. A heat pump heats more slowly than an element and can take a while to catch up after a big morning.
Leaking hot water system? Where it’s leaking matters
- Dripping from the relief valve pipe while heating: a small amount is normal on many mains-pressure storage systems. A constant stream isn’t. That points to a faulty valve or pressure that’s too high.
- Leaking from a fitting or valve on top: usually repairable.
- Water coming from the bottom of the tank or the base: normally means the inner tank has corroded through. That can’t be repaired, so the unit needs replacing. Turn off the cold water to the unit and the gas or power, and call.
Repair or replace?
Plenty of hot water faults are worth fixing: thermocouples, elements, thermostats, relief valves, ignition parts and tempering valves. We’ll give you a straight answer on which way we’d go if it were our own house.
It usually makes sense to replace when the tank itself is leaking, when the unit is well into its second decade, or when the repair costs a big chunk of a new unit. Storage tanks commonly last around 8 to 12 years, depending on the unit and your water. Many manufacturers recommend checking the sacrificial anode at around five years, which can help a tank last longer.
If you’re replacing, see our hot water systems page for the options. You can also look at the 135 L gas storage units we supply.
What to tell us when you call
- Your suburb and whether it’s gas, electric, solar, heat pump or continuous flow.
- The brand and the model sticker on the side, if you can get to it. A photo is perfect: text it to 0406 882 648.
- Whether it’s leaking, and from where.
- Roughly how old it is.
Common questions
- Why is my hot water not working but the gas stove is?
- The gas supply is fine, so the problem is at the hot water unit. The usual suspects are a pilot light that’s gone out, a worn thermocouple, an ignition fault, or on continuous flow units, no power to the unit. If relighting per the instructions on the unit doesn’t work, call a licensed gas fitter.
- Why is there no hot water after a power outage?
- Electric and continuous flow systems can trip or lock out when the power drops. Check the circuit breaker, then check the controller for an error code. Electric storage units also need time to reheat a full tank. If a breaker keeps tripping, don’t keep resetting it. Call us.
- Is it normal for my hot water relief valve to drip?
- A small amount of water during the heating cycle is normal on many mains-pressure storage systems. A constant flow, or water pouring out, isn’t. That usually means a faulty valve or high water pressure, and both need a plumber.
- How long does a hot water system last in Perth?
- Storage systems commonly last around 8 to 12 years, depending on the brand, the water and how well they’re maintained. Water leaking from the bottom of the tank usually means it’s done.
- Can you repair gas hot water systems?
- Yes. McDermott Plumbing does licensed plumbing and gas fitting, including gas hot water repairs and replacements. Call (08) 6187 3999.
Related pages
Last updated 29 September 2026. General information only. Every property is different, so call us to talk about yours.