Hot Water System Sizes - The Right Size For Your Household
Running out of hot water every evening, or paying to heat a tank bigger than you need? Here is how size works, and our licensed plumbers supply and install the system that suits your home at a price agreed before any work starts.
- $0 call-out fee*No charge just to come and look
- Fixed Price QuotesUpfront pricing before work starts
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- Lifetime guaranteeIf our work fails, we fix it
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*No call-out fee during business hours, Monday to Friday 7am to 4pm. Mr Splash VIP lifetime members pay no call-out fee at any time. After-hours and weekend call-outs may attract a fee at our discretion, and we will always confirm it with you before we attend.
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The Hot Water System Sizes We Install
Find the size that matches your household, and you get a fixed price before any work starts.
135 To 170 Litre Gas
Gas storage heats back up quickly, so a smaller tank can suit a couple or a small family.
250 Litre Electric
A common size for a household of three or four on an electric tank.
315 Litre Electric
Suits a bigger family, or a household with two bathrooms in use at once.
400 Litre Electric
For large households on off-peak power, where the tank has to last all day.
Continuous Flow, No Tank
Sized by litres per minute instead of tank size, so it does not run out.
Heat Pump Systems
A tank heated by an outdoor unit, sized much like an electric tank.
Outdoor Gas Storage
Freestanding gas tanks for homes with a gas supply and room outside.
Signs Your Hot Water System Is The Wrong Size
Three situations that bring people to this page, and what to do about each.
No Hot Water Today
If the system has already failed, size matters less than getting the water back on. Call us and we will tell you whether it can be repaired, or quote a replacement sized for your household.
Running Out Every Evening
The household has grown or a second bathroom was added, and the tank empties before everyone has showered. A bigger tank or a continuous flow unit fixes it for good.
Old System, Planning A Change
It still works but it is getting old, and you would rather choose the next one than be rushed. We look at what you have and quote the size and type that suits.
How We Choose The Right Size
Getting hot water system sizes right starts with your household, not the biggest tank on the shelf.
Licensed plumbersLook At What You Have
We read the data plate on your current system for its size, type and age, and ask how many people use hot water and when. That shows whether the old size was ever right.
Upfront pricingCheck What Fits
We check the space, the power or gas supply, and whether a gas unit needs a flue or an outdoor spot. Then you get the options that will actually fit your home.
Fixed price firstSupply And Install
You choose the system, we supply it at a fixed price, fit it with the pipework it needs and test it before we leave. Nothing happens without your go-ahead.
Free Call-Out, Free Quote, Fixed Price
Nothing to pay until you say yes. Here is how it works.
We come out, no call-out fee*
A licensed plumber comes to you, looks at the problem and tells you exactly what is going on. No charge for the visit during business hours.*
You get a fixed-price quote, free
Before any work starts you get the full price in writing. Not an hourly rate, not an estimate that grows once we are in the walls.
You only pay when you say yes
Accept the quote and we start. The price you accepted is the price you pay, however long the job takes. What you see is what you get.
*No call-out fee during business hours, Monday to Friday 7am to 4pm. Mr Splash VIP lifetime members pay no call-out fee at any time. After-hours and weekend call-outs may attract a fee at our discretion, and we will always confirm it with you before we attend.
Video Testimonials
Get The Size Right The First Time
Tell us how many people live in the home and a licensed plumber will call you straight back with options and a fixed price.
- Fixed Price QuotesOnce we know your household and where the system goes, you get one price for the new system fitted and tested. It does not change on the day.
- No Call-Out Fee*Getting a plumber out to look at your current system and measure up costs you nothing during business hours. Nothing is charged until you have said yes to the price.
- Pay Later At 0%The right size system should not wait for payday. Spread the fixed price over a 0% interest payment plan and stop running out of hot water.
*Terms and conditions apply.
Get a Free Hot Water System Quote
60 seconds · no obligation
Hot Water System Sizes FAQs
Answer:
It mostly comes down to how many people shower and how close together. As a rough guide, one to two people suit a smaller tank, three to four people a mid-size tank, and five or more a large tank or a continuous flow unit. We confirm it against your actual household before quoting.
Answer:
On an electric tank, a family of four is often around 250 to 315 litres, depending on whether you are on off-peak power. Gas storage heats back up faster, so a smaller gas tank can do the same job. Two bathrooms in use at once pushes the size up.
Answer:
Small electric units around 50 litres can suit a single person in a unit, a granny flat or a single kitchen or laundry. They run out quickly with back-to-back showers, so they are rarely the right choice for a family home.
Answer:
A gas burner reheats the water much faster than an electric element, especially an off-peak electric tank that only heats overnight. That means a gas tank can be smaller and still keep up.
Answer:
By how many litres of hot water per minute it can deliver, not by tank size. The number on the front of the unit, such as 26, is that flow rate. Homes with more than one shower running at the same time need a higher flow rate.
Answer:
A larger tank keeps more water hot, so it loses more heat standing idle. Buying a tank far bigger than you need wastes energy, which is why sizing to the household matters.
Answer:
It depends on the size, the type and what your home needs to fit it, such as a new flue or gas line. You get one fixed price for the system supplied and installed before any work starts, and there is nothing to pay for us to come and look during business hours. Current Sydney market ranges by system type are in our hot water system prices guide.
Guides That Answer the Question First
Written by our licensed team from real Sydney jobs: what it usually costs, what to check yourself, and when to call. Every price is a published market range, never a sales pitch.
Hot Water System Prices Sydney 2026
Market ranges by system type, a calculator, and repair or replace.
Read the guideNo Hot Water? What to Check First
Five checks that find the cause in ten minutes, system by system.
Hot Water System Leaking
Where the water comes from tells you if it is a valve, a fitting or the tank.
Tempering Valve Explained
Why the tank stores at 60 degrees and the bathroom gets 50, and when it fails.
All our guides are on the Mr Splash blog.
Recent Hot Water System Jobs Across Sydney
Suburbs where we have sized, replaced or worked on hot water systems recently.
Upfront fixed pricing quoted before any work starts. Terms and conditions apply.
