A bloke in Oran Park rang me on a Thursday in July. The tank had let go overnight, the garage floor was wet, and he'd already had one quote over the phone that was double another one, with nobody able to tell him why. That's the trouble with hot water system prices: the number depends on what you're replacing, what you're replacing it with, and what's between the old one and the new one. So here are the real ranges, and what moves them.
The short answer on hot water system installation cost in Sydney for 2026: an electric storage system installed is $920 to $2,875, gas storage is $1,375 to $4,025, and a heat pump is $3,450 to $6,900 before rebates, which take roughly $900 to $1,350 off. Those figures come from Sydney 2026 price guides and they line up with what I see on the ground. Continuous flow (instantaneous gas) is quoted on inspection, because the gas supply, the power point and where it mounts decide most of the cost. A straight like-for-like swap sits at the bottom of each range. A change of fuel, a change of location or a tank up in a roof space pushes you towards the top. If the shower is cold right now, we are a hot water plumber, no call-out fee, across Liverpool, Campbelltown and Camden.
Sydney 2026 price guides put an electric storage hot water system installed at $920 to $2,875, gas storage at $1,375 to $4,025 and a heat pump at $3,450 to $6,900 before rebates of roughly $900 to $1,350. Gas continuous flow is quoted on inspection. A like-for-like swap sits at the bottom of each range; changing fuel or location pushes it up.
Hot water system installation cost by type
| System | Installed price (Sydney 2026 price guides) | Best suited to |
|---|---|---|
| Electric storage | $920 to $2,875 | Like-for-like swaps, off-peak tariffs, homes without gas |
| Gas storage | $1,375 to $4,025 | Homes with mains gas and a tank already outside |
| Heat pump | $3,450 to $6,900 before rebates | Replacing electric or gas storage, solar on the roof, lowest running costs |
| Gas continuous flow | Quoted on inspection | Big households, no room for a tank, never running out |
The unit itself is only part of the installed price. The rest is labour, valves, pipework and taking the old one away. That's why "how much is a new hot water system" is really two questions: what does the unit cost, and what does it take to put it in properly. Which type suits which household, and what size, I've covered in what size hot water system do I need.
What moves the price up or down
These are the things I'm looking at when I quote, and the things worth mentioning when you ring.
Like-for-like or a changeover
Same type, same size, same spot is the cheapest job there is: drain the old tank, swap the valves, connect the new one, commission it, gone in a couple of hours. Electric to heat pump is usually still a same-spot job, but the unit is taller and needs air around it, so sometimes it shifts half a metre. Gas storage to continuous flow means a new gas line (often a bigger one), a flue if it goes inside, a power point for the ignition and new mounting. Electric to gas means running gas to a house that may not have it, and that's a different project altogether.
Where it lives
Outside on a slab is the easy one. A tank in a laundry cupboard in Liverpool or a roof space in an older Casula house adds time and sometimes a second pair of hands. Internal tanks also need a safe tray and drain, which older installs often don't have.
Valves, pipework and the standard
Every new storage install in NSW gets a tempering valve (bathroom hot water limited to 50 degrees), a new temperature and pressure relief valve with its drain line run properly, a cold water expansion valve where needed, isolation valves and, if your mains pressure is high, a pressure limiting valve. On a 15 year old installation most of that is due anyway. Some old installs have none of it, and bringing them up to standard is where the "why is it more than the unit price" question usually comes from.
Timing and disposal
An after-hours emergency changeover costs more than a booked one. If you've isolated the old tank and you can cope with cold showers for a night, wait for business hours; it'll save you money and I'll say so on the phone. Disposal of the old tank is included in my quotes. Ask any plumber whether it's in theirs.
Heat pump rebates: the NSW incentive and federal STCs
If you're replacing an electric or gas storage system with a heat pump, two rebates apply, and they're taken off the invoice rather than claimed afterwards. Federal STCs (small-scale technology certificates) are worth about $490 to $680 on a typical domestic unit. The NSW hot water upgrade incentive adds up to about $640 when you're replacing electric and around $330 when you're replacing gas. Together that's roughly $900 to $1,350 off, with a minimum $220 co-payment, and the job has to go through an accredited provider using an approved model. That brings a heat pump to somewhere near a good gas storage install for most homes. Whether it pays off on your bills depends on your tariff and whether you have solar, and I go through that honestly in heat pump hot water systems explained.
Why hot water system installation is licensed work
In NSW you need a licence to do any plumbing, draining or gasfitting work regardless of cost, and that covers hot water. It's not red tape for its own sake. A storage tank is a pressure vessel full of 60 degree water sitting next to your house; the relief valve, its drain line, the tempering valve and the gas connection are all safety items with rules about how they're installed. A licensed installer issues a compliance certificate at the end, which you'll want for insurance, for a sale, and for the manufacturer's warranty. I hold NSW licence 488158C for plumbing, drainage and gasfitting, so one person does the water, the gas and the paperwork.
How to get an accurate quote over the phone
You can get a real number, not a range, in a five minute call if you send three things: a photo of the compliance plate on the old unit (make, model, litres), a wider photo showing where it sits and the pipes into it, and a rough idea of how many people are in the house. From that I can tell you whether like-for-like makes sense or a heat pump is the better fit, and give you a price before any work starts. If the old unit is on its last legs but not leaking yet, how long hot water systems last has the repair or replace rule of thumb. For a leaking tank the answer is nearly always replace.
Hot water systems prices Sydney, by type
Electric storage is the cheapest to buy and the dearest to run on a standard tariff. Gas storage sits in the middle. Heat pumps cost the most installed, but the federal and NSW incentives close most of the gap and they are the cheapest to run for a family on electric. Continuous flow depends on gas supply and flow rate. Those are the four types we install; which suits your house is a ten minute conversation on inspection, and we quote on inspection rather than over the phone.
Hot water system replacement cost: like for like or upgrade
A like-for-like swap is the quickest and cheapest install because the base, the valves and the pipework are already where the new unit needs them. Moving to a heat pump or changing fuel adds an electrician or a gas line, so the number goes up even after the rebate. Read our how long hot water systems last guide before deciding whether a repair is worth it.
Gas hot water installation costs: what changes the number
Gas storage and continuous flow installs move with the gas line: whether the existing line is big enough for a continuous flow unit, how far it runs, and whether the flue and the location comply. A compliance certificate is issued on every gas job. See gas vs electric hot water for the running-cost side, because that is where gas is losing ground.
When to call a plumber
Ring straight away if the tank is leaking onto electrical gear, if you smell gas, or if hot water is pouring from the relief line and you can't isolate it. Ring in business hours if the old unit has died but isn't leaking, if you're planning a renovation and want the hot water sorted before the walls close, or if you want a heat pump quote with the rebates worked out. Done right. Done once.
Monarch Civil & Plumbing covers South West Sydney and the Macarthur region for hot water system installation, from Liverpool and Casula out to Oran Park and Camden, alongside all our plumbing services. If you need a plumber in Oran Park or a plumber in Liverpool, call 0455 222 292 with a photo of the old unit and I'll give you a price before I start.
Related guides: what size hot water system you need and heat pump hot water.
Need it sorted? Ring 0455 222 292 any hour or book online. Monarch Civil & Plumbing is a hot water plumber, no call-out fee: repairs where they are worth it, same-day replacement where we can, and the NSW rebate sorted.
No hot water in Campbelltown, Liverpool or Camden?
Campbelltown has its own page: hot water service Campbelltown. For Liverpool, Camden and the rest of South West Sydney start with hot water systems, then the suburb pages plumber Liverpool and plumber Camden. Same-day replacement for common electric and gas sizes where stock allows, no call-out fee, NSW rebate sorted for heat pumps.
Frequently asked
How much to install a hot water system in Sydney?
Sydney 2026 price guides put an electric storage system installed at $920 to $2,875, gas storage at $1,375 to $4,025 and a heat pump at $3,450 to $6,900 before rebates. Gas continuous flow is quoted on inspection. Like-for-like changeovers sit at the low end; a change of fuel, a new location, a roof space install or an after-hours job pushes you towards the top of the range.
How much is a new electric hot water system?
Installed, $920 to $2,875 according to Sydney 2026 price guides. The unit is only part of that. The rest is labour, a new tempering valve and relief valve, isolation valves, any pipework changes and removing the old tank. A same-size, same-spot swap on an outdoor slab is the cheapest version. An internal tank, a bigger capacity or an after-hours changeover costs more.
Are heat pump hot water systems worth the extra cost?
Often, if you're replacing electric storage and you have a daytime tariff or solar. Rebates of roughly $900 to $1,350 (federal STCs plus the NSW incentive) bring the installed price down, and running costs are well below an electric tank. They're less compelling on cheap off-peak power or in a cramped, noise-sensitive spot. I'll tell you straight if it doesn't stack up for your house.
Can I install a hot water system myself in NSW?
No. NSW requires a licence for any plumbing, draining or gasfitting work regardless of cost, and hot water is part of that. The install involves a pressure relief valve, a tempering valve set to 50 degrees and sometimes gas, all of which are safety items, and the licensed installer issues a compliance certificate you'll need for insurance and for the manufacturer's warranty.
How long does a hot water system installation take?
A like-for-like storage changeover on an outdoor slab is usually two to three hours, and you'll have hot water again that evening. Electric to heat pump is similar, a bit longer if the unit needs relocating. A gas storage to continuous flow conversion with a new gas line and flue can take most of a day. I'll give you a time frame along with the price.
Do you take the old hot water system away?
Yes, removal and disposal of the old unit is included in my quotes. It's worth asking any plumber whether it's in theirs, because a 250 litre tank is not something you want left on the driveway. Old steel tanks go to scrap metal recycling, and any leftover valves and pipework come away with the job.
Licensed plumber and drainer based in Austral, 13+ years in the trade, working across Liverpool, Fairfield and the Macarthur region. About Paul