New Hot Water System: How to Choose the Right Replacement for Your Home

Oct 29, 2024

Need a new hot water system? The right choice depends on your household size, number of bathrooms, shower habits, energy source, installation location, access, water pressure, electrical requirements, gas type, drainage and whether you want supply only or an eligible supplied-and-installed option.

Electric storage, gas storage, instant gas, instant electric, heat pump and solar hot water systems all suit different homes. A simple like-for-like replacement may be the easiest path, but it is not always the best option if your old system was too small, expensive to run or no longer suited to your household.

Installed Today makes it easy to compare and order hot water systems online, including electric hot water systems, gas hot water systems, instant gas hot water systems and heat pump hot water systems. Supply-only ordering is available across major Australian metro areas, with selected supplied-and-installed options available on eligible products in Brisbane and Gold Coast service areas.

Quick Answer: What Should You Check Before Buying a New Hot Water System?

Before buying a new hot water system, check the current system type, household hot water demand, energy source, installation location and whether your old system was meeting your needs.

As a general guide:

Electric storage hot water can suit simple replacements and homes without gas
Gas storage hot water can suit homes already using natural gas or LPG that want stored hot water
Instant gas hot water can suit homes wanting continuous flow hot water without a large tank
Heat pump hot water can suit energy-focused homes with suitable outdoor space, airflow and drainage
Solar hot water can suit homes with suitable roof space, sun exposure and booster planning
Instant electric hot water can suit small point-of-use applications
Supply-only pricing usually covers the product only
Supplied-and-installed options are only available on selected eligible products and locations

Before ordering supply only, confirm the selected model, size, gas type, electrical requirements, water pressure, access, valves, drainage and installation suitability with your licensed installer.

When Do You Need a New Hot Water System?

You may need a new hot water system if your existing unit is no longer reliable, suitable or economical to keep using.

Common signs include:

No hot water
Hot water running out quickly
Rust or corrosion on the unit
Leaks around the tank or fittings
Discoloured hot water
Unusual noises
Error codes on instant gas systems
Poor recovery after showers
Water temperature fluctuating
The unit is old and nearing the end of its service life
Repair costs are becoming harder to justify
The household has grown and demand has changed
You want to compare a more energy-efficient option

If your current system has been struggling for a while, do not automatically replace it with the same size or type. It may be worth comparing other options first.

Main Types of New Hot Water Systems

The main hot water system types are:

Electric storage
Gas storage
Instant gas
Instant electric
Heat pump
Solar hot water

Each option has different product costs, installation requirements, running cost potential and suitability factors.

Electric Hot Water Systems

Electric hot water systems are common in Australian homes and are often chosen for simple like-for-like replacements. They use an electric element to heat water stored inside a tank.

Electric storage may suit:

Homes without natural gas or LPG
Existing electric storage replacements
Rental properties
Small, medium and larger households
Homes already wired for electric hot water
Customers wanting a familiar tank-style system

Electric hot water installation checks include:

Correct tank size
Electrical supply
Element size
Indoor or outdoor suitability
Access for delivery
Base or slab condition
Valve requirements
Drainage and overflow
Tempering valve requirements
Old unit removal and disposal

Common electric storage categories include:

Popular electric storage options include:

If your old electric system regularly ran out of hot water, replacing it with the same size may repeat the problem.

Gas Hot Water Systems

Gas hot water systems can suit homes already using natural gas or LPG.

Gas hot water systems usually fall into two categories:

Gas storage hot water
Instant gas hot water

Gas hot water may suit homes that:

Already have natural gas or LPG
Want gas storage or continuous flow hot water
Have suitable outdoor installation space
Have suitable gas pipe sizing
Have suitable water pressure
Want a gas-style replacement

Gas work must be completed by a licensed gas fitter. Natural gas and LPG systems are not interchangeable, so the correct gas type must be selected before ordering.

Gas Storage Hot Water Systems

Gas storage systems heat and store water in a tank. They can suit homes already using gas that want stored hot water ready for daily use.

Gas storage may suit:

Existing gas storage replacements
Homes already set up for natural gas or LPG
Households wanting a tank-style system
Properties with suitable outdoor space
Homes where stored hot water suits the usage pattern

Common gas storage categories include:

Popular gas storage options include:

Gas storage can be practical where the old system worked well and the installation location is still suitable.

Instant Gas Hot Water Systems

Instant gas hot water systems, also called continuous flow gas hot water systems, heat water as it passes through the unit. They do not store a full tank of hot water.

Instant gas may suit:

Homes wanting continuous flow hot water
Homes with suitable natural gas or LPG
Homes with suitable gas pipe sizing
Homes with suitable water pressure
Properties with outdoor wall space
Households wanting a compact alternative to a storage tank

Common instant gas sizes include 16L, 20L and 26L.

A 26L instant gas hot water system may suit some family homes, but only where gas pipe sizing and water pressure support the selected unit.

Popular instant gas options include:

External gas hot water units are designed for outdoor installation unless the specific manufacturer model is approved for internal flued installation.

Heat Pump Hot Water Systems

A heat pump hot water system is an electric-style storage system that uses heat from the surrounding air to help heat stored water.

Heat pump hot water may suit homes that:

Want to reduce hot water electricity use
Are replacing an older electric storage system
Have suitable outdoor space
Have clear airflow around the unit
Can manage condensate drainage
Have suitable electrical supply
Have a sensible noise location
Want to pair hot water operation with rooftop solar where timing suits

Heat pumps are not automatically the best option for every home. They need suitable airflow, drainage, access, electrical suitability and noise placement.

Many homes compare:

Popular heat pump options include:

Solar Hot Water Systems

Solar hot water systems use roof-mounted collectors to capture heat from the sun and transfer it into stored water. Most systems include an electric or gas booster for cloudy weather or high-demand periods.

Solar hot water may suit homes with:

Suitable roof space
Good sun exposure
Minimal shading
Suitable roof orientation
A suitable booster setup
Long-term energy efficiency goals
Space for collectors and storage

Solar hot water can reduce grid energy use where the property suits the technology, but it is not always the simplest replacement. Roof access, shading, collector placement, booster type, maintenance and upfront cost all matter.

For some homes, heat pump hot water may be easier to compare because it does not need roof-mounted collectors.

Instant Electric Hot Water Systems

Instant electric hot water systems heat water on demand using electric heating elements.

They may suit:

Small sinks
Offices
Kitchenettes
Granny flats
Low-demand fixtures
Point-of-use hot water
Space-limited applications

Instant electric systems can have high electrical requirements, especially if used for showers or higher flow rates. They are not always suitable for whole-home hot water.

Before ordering an instant electric unit, confirm:

Electrical capacity
Circuit requirements
Switchboard suitability
Flow rate
Intended fixture use
Water pressure
Installation location
Whether a licensed electrician is needed

Storage vs Continuous Flow Hot Water

A new hot water system may be a storage system or a continuous flow system.

System Type	How It Works	Common Examples
Storage hot water	Heats and stores water in a tank	Electric storage, gas storage, heat pump, solar
Continuous flow hot water	Heats water as it flows through the unit	Instant gas, selected instant electric systems

Storage systems can suit homes wanting stored hot water ready for use. Continuous flow systems can suit homes wanting compact hot water without a full-size tank, but they must be correctly sized and supported by the property.

Electric vs Gas vs Heat Pump vs Solar: Which New System Should You Choose?

System Type	Best Suited To	Key Checks
Electric storage	Simple replacements and homes without gas	Tank size, electrical supply, access and drainage
Gas storage	Homes with natural gas or LPG wanting stored hot water	Correct gas type, outdoor location and valve setup
Instant gas	Continuous flow hot water where gas supply suits	Gas pipe sizing, water pressure and correct gas type
Heat pump	Energy-focused homes with suitable outdoor space	Airflow, drainage, access, noise and electrical suitability
Solar hot water	Homes with suitable roof space and sun exposure	Roof orientation, shading, booster and collector setup
Instant electric	Small point-of-use applications	Electrical capacity, circuit requirements and flow rate

The best new hot water system is the one that fits your home’s demand and installation conditions.

Choosing the Right Size New Hot Water System

Correct sizing is one of the most important parts of choosing a new hot water system.

When choosing size, consider:

Number of people in the home
Number of bathrooms
Shower length
Bath use
Kitchen use
Laundry use
Morning and evening peak demand
Whether multiple showers run at once
Existing system size
Whether the old system ran out of hot water
Available energy source
Installation space
Recovery rate
Water pressure
Gas pipe sizing where relevant

For electric storage, many homes compare 250L, 315L and 400L systems.

For heat pumps, many homes compare 200L–280L and 280L-plus systems.

For instant gas, common sizes include 16L, 20L and 26L.

New Hot Water System for Small Homes

Small homes may suit:

Smaller electric storage systems
16L instant gas where gas supply is suitable
Compact instant electric systems for point-of-use needs
Selected heat pumps where outdoor space and airflow suit

Avoid oversizing unless household demand is expected to increase.

New Hot Water System for Family Homes

Family homes usually need more careful sizing because hot water demand often peaks in the morning and evening.

Common options include:

250L electric storage
315L electric storage
Medium heat pump hot water
20L instant gas
26L instant gas where the site supports it
Gas storage where natural gas or LPG is available

If your current system runs out of hot water, review the size and system type before ordering a replacement.

New Hot Water System for Homes Without Gas

Homes without gas usually compare:

Electric storage hot water
Heat pump hot water
Instant electric hot water for small point-of-use applications
Solar hot water where roof conditions suit

Electric storage can be a simple replacement. Heat pump hot water may be worth comparing if the home has suitable outdoor space, airflow, drainage and electrical supply.

New Hot Water System for Homes With Gas

Homes with natural gas or LPG may compare:

Gas storage hot water
Instant gas hot water
Heat pump hot water if moving toward electric-style hot water
Electric storage where a non-gas replacement is preferred

If choosing instant gas, confirm gas pipe sizing and water pressure before ordering.

Like-for-Like Replacement vs Changing System Type

A like-for-like replacement can be simpler, but it is not always the right answer.

Like-for-Like Replacement

This may involve replacing:

Electric storage with electric storage
Gas storage with gas storage
Instant gas with instant gas
Heat pump with heat pump

Like-for-like can suit homes where the old system worked well and the installation location remains suitable.

Changing System Type

This may involve changing:

Electric storage to heat pump
Gas storage to instant gas
Electric storage to gas
Solar hot water to heat pump
Storage hot water to instant hot water
Indoor system to outdoor system

Changing system type can involve extra plumbing, electrical work, gas work, drainage, access or compliance requirements.

What Can Add Cost to a New Hot Water System?

The final cost can vary depending on the product and the property.

Common cost factors include:

System type
Tank size or flow rate
Existing system type
Like-for-like replacement vs relocation
Indoor vs outdoor location
Tight access
Stairs or difficult delivery path
Existing valve condition
Tempering valve requirements
Pressure limiting valve requirements
Expansion control valve requirements
Drainage and overflow points
Electrical supply
Gas pipe sizing
Water pressure
Pipework route
Condensate drainage for heat pumps
Roof access for solar
Old unit removal
Disposal
Non-compliant existing installation
Base or slab condition

A product-only price should not be treated as a full installed price.

What Is Not Included in Supply-Only Hot Water Pricing?

For supply-only products, the listed product price generally covers the product only.

It does not usually include:

Installation labour
Plumbing alterations
Electrical work
Gas work
New valves
Pipework changes
Gas pipe upgrades
Drainage changes
Condensate drainage for heat pumps
Tempering valve upgrades
Pressure limiting valve upgrades
Expansion control valves
Old unit removal
Disposal
Compliance upgrades
Concrete bases or slab work
Flue kits unless listed
Temperature controllers unless listed
Relocation of the system
Rebate administration
Site assessment

Always check the product page and confirm full site requirements with your licensed installer before ordering supply only.

Supply-Only vs Supplied-and-Installed New Hot Water Systems

Installed Today offers supply-only ordering across major Australian metro areas. This can suit customers who already have a licensed installer organised and want to order the product online.

Supply-only may suit you if:

Your installer has confirmed the correct product
The system size suits your household
The correct gas type has been selected where relevant
Electrical requirements have been checked
Water pressure has been reviewed
Access and drainage are suitable
You understand what is not included in the product price

Selected supplied-and-installed options are available on eligible products in Brisbane and Gold Coast service areas. Availability depends on the product, address and installation requirements.

Before choosing a supplied-and-installed option, check:

Whether the product is eligible
Whether your address is eligible
Whether the installation is like-for-like
Whether valves are included or extra
Whether electrical work is included or extra
Whether gas work is included or extra
Whether old unit removal is included
Whether disposal is included
Whether pipework changes are included
Whether drainage changes are included
Whether compliance upgrades may be extra
Whether rebates or STCs are included, excluded or handled separately

Do not assume every product or every location has an installed option.

Rebates, STCs and Incentives

Some hot water systems, especially heat pumps and solar-style upgrades, may be eligible for rebates, STCs or other incentives depending on the product, location, supplier pathway and current program rules.

These incentives can change.

Before relying on a rebate or discount, confirm:

Whether the selected product qualifies
Whether your property qualifies
Whether the old system type matters
Whether supply-only purchases are eligible
Whether an approved supplier or installer is required
Whether pre-approval is needed
Whether the incentive is applied upfront or claimed later
Whether the rebate or STC value is already included in the price

A rebate can improve value, but the system still needs to suit the home.

Maintenance After Buying a New Hot Water System

A new hot water system still needs maintenance to perform safely and reliably.

Maintenance requirements vary by system type, water quality, model and installation location.

General maintenance considerations include:

Checking for leaks
Watching for rust or corrosion
Keeping the area around the unit clear
Following manufacturer servicing guidance
Checking valves where required
Checking the anode where applicable
Keeping heat pump airflow clear
Checking heat pump condensate drainage
Using a licensed gas fitter for gas systems
Using a licensed electrician for electrical faults

Do not attempt plumbing, gas or electrical repairs yourself.

Brisbane and Gold Coast Considerations

For Brisbane and Gold Coast homes, new hot water system choice often depends on the existing unit, outdoor space, access, drainage and energy source.

Common considerations include:

Replacing older electric storage systems
Comparing electric storage with heat pump upgrades
Natural gas vs LPG availability
Outdoor wall space for instant gas
Gas pipe sizing for 26L systems
Heat pump airflow and noise placement
Condensate drainage
Tight side access
Existing valve condition
Old unit removal and disposal
Whether the selected product is eligible for supplied-and-installed options

Installed Today offers selected supplied-and-installed options on eligible products in Brisbane and Gold Coast service areas, with supply-only ordering available across major Australian metro areas.

Trusted Hot Water Brands to Compare

Installed Today stocks a range of major hot water brands, including:

Brand matters, but system type, size, gas type, water pressure, installation location and household demand matter more than brand alone.

Common Mistakes When Buying a New Hot Water System

Choosing Only by Product Price

A cheap system may cost more long term if it is undersized, inefficient or unsuitable for the property.

Replacing the Same Size Without Checking Demand

If the old system ran out of hot water, the same size may not be enough.

Ignoring Gas Type

Natural gas and LPG systems are different. Always choose the correct model.

Choosing 26L Instant Gas Without Checking the Site

A 26L instant gas system needs suitable gas pipe sizing and water pressure.

Choosing Heat Pump Without Checking Location

Heat pumps need clear airflow, condensate drainage, access, electrical suitability and sensible noise placement.

Assuming Instant Electric Suits the Whole Home

Instant electric systems can have high electrical demand and may be better suited to point-of-use applications.

Assuming Rebates Are Guaranteed

Rebates, STCs and incentives can change and may depend on product, location, supplier and installer pathway.

Assuming Supply-Only Includes Installation

Supply-only generally means product only unless installation is selected or clearly shown.

Before Ordering Checklist

Before ordering a new hot water system, confirm:

Current system type
Current system size
Whether the old system ran out of hot water
Number of people in the home
Number of bathrooms
Shower habits
Peak hot water demand
Electric, natural gas or LPG availability
Correct gas type where relevant
Electrical requirements
Gas pipe sizing for instant gas
Water pressure
Heat pump airflow and drainage
Solar roof suitability where relevant
Outdoor or indoor suitability
Access for delivery and installation
Drainage and overflow requirements
Whether new valves may be needed
Whether old unit removal is included
Whether disposal is included
Whether rebates or STCs may apply
Whether supply-only affects rebate eligibility
Whether supply-only or supplied-and-installed is the right option
Installer confirmation before buying supply only

Frequently Asked Questions

What is the best new hot water system?

The best new hot water system depends on your household size, bathrooms, shower habits, energy source and installation location. Electric, gas, instant gas, heat pump and solar systems all suit different homes.

Should I replace my hot water system with the same type?

Sometimes. A like-for-like replacement may be practical if the old system worked well. If it ran out of hot water, cost too much to run or no longer suited the home, compare other options before ordering.

Is electric or gas hot water better?

Electric hot water can suit homes without gas or simple replacements. Gas hot water can suit homes already set up for natural gas or LPG. Natural gas and LPG systems are not interchangeable.

Are heat pump hot water systems worth it?

A heat pump may be worth considering if your home has suitable outdoor space, airflow, condensate drainage, electrical supply and noise placement. It may reduce electricity use compared with standard electric storage in the right location.

Is solar hot water better than heat pump hot water?

It depends on the property. Solar hot water needs suitable roof space, sun exposure and booster planning. Heat pumps need suitable outdoor space, airflow, drainage and electrical supply.

What size new hot water system do I need?

The right size depends on people in the home, bathrooms, shower habits, bath use, peak demand and whether the old system ran out. Common options include 250L, 315L and 400L electric storage, 200L–280L heat pumps and 16L to 26L instant gas systems.

Does supply-only hot water pricing include installation?

No. Supply-only generally means the product only unless installation is selected or clearly shown. Installation, valves, electrical work, gas work, pipework, drainage, removal, disposal and compliance upgrades are usually separate.

Can I install a new hot water system myself?

No. Hot water systems involve plumbing, gas, electrical work, water pressure, valves, drainage and compliance requirements. Use licensed trades where required.

Are hot water rebates available?

Some heat pump and solar-style systems may be eligible for rebates, STCs or incentives depending on product, location and current program rules. Eligibility can change, so check before ordering.

What should I check before buying supply only?

Confirm the system type, size, gas type, electrical requirements, water pressure, access, drainage, valves and installation suitability with your licensed installer before ordering supply only.

Final Word

A new hot water system should be chosen around your home, not just the cheapest product price. Electric storage can suit simple replacements. Gas storage and instant gas can suit homes already using natural gas or LPG. Heat pump hot water can suit energy-focused homes with suitable outdoor space. Solar hot water can suit homes with suitable roof conditions. Instant electric can suit smaller point-of-use applications.

Before ordering supply only through Installed Today, confirm the selected product with your licensed installer. If choosing a supplied-and-installed option in an eligible Brisbane or Gold Coast service area, check exactly what is included before placing the order.

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