No hot water? What to check before you call

A fair share of the "no hot water" calls we take around Parramatta are not broken systems at all. They are a tripped breaker, an empty tank that will not refill until after 10pm because of how the local electricity network switches it, or a tempering valve quietly doing the wrong thing. Fifteen minutes of checking at your end can save you a call-out fee, and if it turns out to be real, you will be able to tell us something useful when you ring.

Here is the order I would work through it, starting with the checks that cost nothing.

The short answer

Check whether it is the whole house or one tap, then look at the switchboard for a tripped breaker on the hot water circuit. If you are on an electric storage tank in Parramatta, remember the network only feeds it overnight, so resetting a breaker at breakfast will not give you hot water until tomorrow morning. Gas units usually need the pilot or the gas supply checked. Call a plumber if you find water under the tank, smell gas, or the unit is over about ten years old.

1. Is it every tap, or just one?
2. Check the switchboard for a tripped hot water breaker
3. Work out which type of system you actually have
4. Electric: understand the overnight controlled load
5. Gas: check the pilot, the gas, and the isolation valve
6. In an apartment, ask a neighbour before you call anyone

On this page

1. Is it the whole house or one tap?
2. Check the switchboard
3. Work out which system you have
4. Electric storage: the controlled load trap
5. Gas: pilot, supply and isolation
6. Heat pumps and solar
7. If you live in an apartment
8. Why Parramatta systems fail the way they do
9. Four things that make it worse
10. Emergency, or can it wait?
11. How to stop it happening again

1. Is it the whole house, or one tap?

This one question splits the problem in half, so do it first.

Run the hot tap at the kitchen sink, then the bathroom basin, then the shower. If every outlet in the house is cold, the system itself has stopped making hot water and the rest of this guide applies. If the kitchen runs properly hot but the bathroom is lukewarm, the tank is almost certainly fine and you are looking at a tempering valve, which is a much smaller job.

That difference matters because of how hot water is regulated here. Australian Standard AS/NZS 3500.4 requires stored hot water to be held at a minimum of 60 degrees so legionella cannot establish itself, then tempered back down so no more than 50 degrees reaches bathroom and hand basin outlets. A tempering valve does that mixing, and kitchen taps are generally not tempered. So a house where the kitchen is scalding and the shower is tepid is telling you exactly where to look.

2. Check the switchboard before anything else

Go and look at your meter board. On most Parramatta homes with an electric tank there is a separate breaker or fuse just for the hot water, often labelled "HWS" or "off peak", sitting apart from the general power and lighting circuits.

If it has tripped, that is your answer, and it is free to reset. If it trips again straight away, stop there and call us, because a breaker that will not hold usually means a failed element or water where it should not be.

Now the part that catches people out, and it is specific to this side of Sydney. Resetting that breaker at eight in the morning will not give you hot water at nine. Read the next section before you assume the reset did not work.

3. Work out which system you actually have

Plenty of people genuinely do not know, and the answer changes everything that follows. Go and look at the unit, usually on a side path, in the laundry, or in a cupboard.

• Electric storage. A tall metal cylinder with no flue, a small electrical box on the side, and a valve near the base with a copper drain line.
• Gas storage. Same cylinder shape, but with a flue on top and a gas line running to it.
• Instantaneous gas. A flat rectangular box on the wall, no tank at all. Common on the newer builds and the townhouse stock.
• Heat pump. A tank with what looks like an air conditioner bolted to it or sitting beside it. It hums when running.
• Solar. Roof panels feeding a roof or ground tank, nearly always with an electric or gas booster.

Photograph the compliance plate while you are there. Brand, model, capacity in litres and the date stamp tell a plumber more in one glance than ten minutes on the phone.

4. Electric storage: the controlled load trap

This is the single most useful thing on this page for a Parramatta household, and it is the bit that generic Sydney plumbing advice gets wrong.

Parramatta is in the Endeavour Energy network, not Ausgrid. Most older electric storage tanks around here sit on a controlled load tariff, which means the network, not you, decides when the tank is allowed to draw power. Under Endeavour's Controlled Load 1, supply to the tank may not be available between 7am and 10pm, and is made available for selected periods between 10pm and 7am. In plain terms, your tank gets one heat overnight, and that is the day's hot water.

So if you emptied the tank at 6pm, nothing is broken. It is simply not allowed to reheat for another four hours. If you reset a tripped breaker in the morning, the relay will not energise until that night, and you will have hot water the following morning rather than by lunchtime.

This is exactly where advice written for the eastern and northern suburbs falls over. Ausgrid updated its Controlled Load 1 switching times in July 2024 so those tanks can pick up daytime hours while solar is plentiful. Endeavour's Controlled Load 1 did not follow, and still shuts the tank out between 7am and 10pm. Endeavour's Controlled Load 2 is the more flexible one, allowing supply for restricted periods of up to 17 hours in any 24, so a tank on that tariff can get a daytime run.

5. Gas: pilot, supply and isolation

Parramatta's gas is distributed by Jemena Gas Networks, and gas hot water fails differently to electric. There is no overnight window to wait for, so if a gas unit has stopped, something has actually stopped it.

Older gas storage tanks have a standing pilot that can blow out, with a small viewing window near the base to check it. Many print a relighting sequence on the unit itself, and if yours does, it is reasonable to follow it once. Newer units and almost all instantaneous heaters use electronic ignition, so there is nothing to relight and a unit that will not fire needs a licensed gas fitter.

Before assuming the worst, check whether your other gas appliances still work. If the cooktop will not light either, the problem is upstream of the hot water unit. Instantaneous heaters also need power, so check their plug or breaker has not been switched off.

If you can smell gas at any point, stop. Do not relight anything, do not touch switches, get everyone outside and call for help. Gas work in NSW must be done by a licensed gas fitter regardless of how simple it looks, which is why we handle it under gas fitting rather than general plumbing.

6. Heat pumps and solar

Heat pumps have become common on replacement jobs around here, and they behave differently again. A heat pump recovers a tank over hours rather than minutes, so a heavy morning can leave you short at night even when the unit is perfectly healthy. Endeavour allows a heat pump on Controlled Load 2 provided the tank is at least 250 litres, and once it is on that tariff it cannot be shifted back to Controlled Load 1.

Check the outdoor unit is actually running and that a fence, a bin or an overgrown shrub has not blocked its airflow. Most heat pumps also carry a small electric backup element, and if that is quietly doing all the work because the compressor has failed, the first sign is a power bill rather than a cold shower. The same goes for a solar system running permanently on its booster.

7. If you live in a Parramatta apartment, check with a neighbour first

This deserves its own step here more than in most suburbs. At the 2021 Census, 85.6 per cent of dwellings in the suburb of Parramatta were flats or apartments, against 7.7 per cent separate houses. Across the wider City of Parramatta local government area, 63.2 per cent of dwellings were medium or high density, compared with 46 per cent for Greater Sydney.

That changes who you should be calling. A lot of the CBD and Westmead towers run central hot water plant or shared risers, where one failure takes out a whole line of units. If your neighbours are cold too, it is a common property matter and strata should be organising it, not you. Booking a plumber for a building fault means paying for a visit that ends at the front door of the plant room.

If it is only your unit, then it is your own system, and it is yours to sort out. Older converted blocks and townhouses around Harris Park and North Parramatta often have an individual tank tucked into a cupboard or on a balcony, and those behave exactly like a house.

8. Why Parramatta hot water systems fail the way they do

Once you have ruled out the cheap causes, it helps to know what actually kills tanks around here, because it is not what most plumbing blogs claim.

It is not limescale. Parramatta is supplied through Sydney Water's Prospect system, fed from Warragamba, and hardness there sits at roughly 50 mg/L, comfortably inside the soft range that starts below 60 mg/L. You will read endlessly that scale is furring up your element. It is not true here. Soft water also means no protective mineral layer forms inside the tank, so the sacrificial anode is carrying the entire corrosion load on its own.

So it is the anode and the element. A spent anode is the most common reason a local tank reaches the end of its life early, and it is a cheap part that almost nobody checks. Elements burn out, thermostats drift, and once a tank has started weeping from the base, it has told you what it wants.

Old pipework is doing its share. Plenty of pre-1970s homes in Harris Park, North Parramatta and Granville still run original galvanised steel. Galvanised pipe corrodes from the inside out and narrows as it goes, so a hot water complaint in those streets is sometimes a flow problem in the pipe rather than a heat problem in the tank.

The ground moves under the buried lines. Much of Parramatta sits on Wianamatta shale, a reactive clay that swells when wet and shrinks when dry. It works buried joints apart over the years, which is why an underground hot line can start leaking without anything above ground giving it away. A tank that never seems to hold its heat, with no visible leak and a water bill creeping upward, is worth investigating properly rather than replacing.

9. Four things that make it worse

• Resetting the breaker over and over. Once is fine. If it trips again, leave it off and call. Re-energising a faulted circuit repeatedly is how a small repair becomes a replacement.
• Turning the thermostat up to compensate. The tank has to sit at 60 degrees or above anyway. Cranking it does not create more hot water, it just runs a failing element harder.
• Ignoring a dripping relief valve. One that weeps occasionally is doing its job. One that runs constantly is telling you about pressure or a failing valve, and it is quietly costing you water.
• Assuming the tank is fine because it is only nine years old. If the anode has never been checked, nine years is about when the bill arrives. Checking one costs far less than the flooded laundry you get instead, which we cover in our guide on what to do in the first ten minutes of a burst pipe.

10. When it is a real emergency, and when it can wait

Being honest about this matters, because plenty of people pay for an after-hours visit they did not need.

Call straight away if: you can smell gas anywhere near the unit; there is water pooling under or running from the tank; the hot water circuit trips the moment you reset it; water is anywhere near the switchboard or electrical fittings; or the water coming out is scalding rather than merely hot, which points at a failed tempering valve and is a genuine burn risk for children and older people.

It can almost certainly wait until business hours if: the tank is simply empty and it is an Endeavour controlled load system, since it will refill overnight regardless of who you call; the kitchen tap is hot and only the bathroom is cool, which is a tempering valve and not urgent; or the water is warm rather than hot and nothing is leaking.

If you are not sure which one you are in, ring and describe it. We would rather tell you to wait until Tuesday than charge you for a Saturday night.

11. How to stop it happening again

• Have the anode checked. On soft Prospect-supplied water it is the part doing all the protective work, and replacing one is a fraction of the cost of replacing a tank.
• Match the tank to the household, not the house. On Endeavour Controlled Load 1 you get one heat a night, so capacity is everything. An extra person in the house often means an extra 100 litres.
• Ask your retailer about Controlled Load 2 if you keep running out in the evenings. It allows supply for up to 17 hours in any 24, which changes the arithmetic completely.
• Test the relief valve once a year. Lift the lever briefly, let it snap shut, and make sure it stops. If it keeps running, book it in.
• Note the install date. Write it on the unit in permanent marker. Knowing whether you are at year six or year fourteen turns a panic decision into a planned one, and it is the first thing we ask when quoting hot water repairs or a replacement.

The short version

• Check whether it is the whole house or just the bathroom before anything else. Bathroom only usually means the tempering valve, not the tank.
• Parramatta is Endeavour Energy, and Controlled Load 1 keeps supply off between 7am and 10pm, so a reset in the morning gives you hot water tomorrow.
• Hard water is not your problem here. On soft Prospect water it is the anode and the element that go.
• In an apartment, ask a neighbour first. Central plant failures are strata's job, not yours.
• Gas smell, water under the tank, or a breaker that will not hold are the three things worth calling about at any hour.