Hot Water Storage Systems: Electric, Gas, Heat Pump and Solar Storage Guide

Oct 8, 2024

A hot water storage system heats water and stores it in a tank so it is ready when your household needs it. Storage systems are common in Australian homes because they can provide a reliable supply of hot water for showers, baths, kitchen use and laundry.

The right storage hot water system depends on your household size, number of bathrooms, shower habits, energy source, installation location, running cost goals and whether you want a standard electric tank, gas storage unit, heat pump or solar-style storage system.

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

Quick Answer: What Is a Hot Water Storage System?

A hot water storage system heats water inside a tank and keeps it ready for use.

The main storage hot water options are:

Electric storage hot water systems for simple replacements and homes without gas
Gas storage hot water systems for homes already connected to natural gas or LPG
Heat pump hot water systems for energy-focused homes with suitable outdoor space, airflow and drainage
Solar hot water systems for homes with suitable roof space, sun exposure and booster planning

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

How Hot Water Storage Systems Work

A storage hot water system holds water in a tank and heats it using electricity, gas, heat pump technology or solar energy with a booster.

The basic process is:

Cold water enters the storage tank
The system heats the water
The tank stores the hot water ready for use
Hot water is drawn from the tank when a tap or shower is used
Cold water refills the tank and is reheated

Storage systems are different from instant gas hot water systems, which heat water only as it flows through the unit.

A storage system can be a practical choice where the household wants stored hot water available for peak morning or evening use.

Electric Storage Hot Water Systems

Electric hot water systems are one of the most common storage options in Australian homes. They use an electric element to heat water inside a tank.

Electric storage can suit:

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

Common size categories include 250L electric hot water systems, 315L electric hot water systems and 400L electric hot water systems.

A 250L electric storage system may suit many small-to-medium households, while larger homes or higher-demand families may need 315L or 400L. If your old system was already running out of hot water, replacing it with the same size may repeat the same issue.

Popular electric storage options include:

Gas Storage Hot Water Systems

Gas hot water systems include gas storage systems and instant gas systems. Gas storage systems heat and store water in a tank using natural gas or LPG.

Gas storage can suit homes that:

Already have natural gas or LPG
Want stored hot water
Prefer gas over electric storage
Have suitable outdoor installation space
Want fast recovery compared with some electric storage setups
Have household demand that suits a tank-style gas system

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

Common gas storage categories include:

Product examples include:

Heat Pump Storage Hot Water Systems

A heat pump hot water system is also a storage hot water system, but it heats water differently from a standard electric tank.

Instead of relying only on an electric element, a heat pump uses heat from the surrounding air to help heat stored water. In the right location, this can reduce electricity use compared with standard electric storage.

A heat pump may suit homes that:

Want to reduce hot water energy 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 heating with rooftop solar where timing and usage suit

A heat pump is not automatically the best choice for every home. It needs suitable airflow, drainage, access, outdoor placement and noise consideration.

Many households compare medium heat pump hot water systems 200L–280L, while larger households may need large heat pump hot water systems. Customers wanting smart features may also compare Wi-Fi enabled heat pump hot water systems.

Popular heat pump options include:

Solar Storage Hot Water Systems

Solar hot water systems are also storage systems. They use roof-mounted collectors to capture heat from the sun and transfer it to water stored in a tank. Most systems include an electric or gas booster for cloudy weather or higher-demand periods.

Solar hot water may suit homes with:

Suitable roof space
Good sun exposure
Minimal shading
Suitable roof orientation
Long-term energy efficiency goals
Space for the tank and collector arrangement
A suitable booster setup

Solar storage hot water can reduce grid energy use where conditions suit, but it is not always the simplest replacement. Roof suitability, shading, booster type, maintenance and upfront cost all matter.

For some homes, a heat pump may be easier to compare than roof-mounted solar hot water, especially where roof space, shading or access is a concern.

Storage Hot Water vs Continuous Flow Hot Water

Storage hot water systems and continuous flow systems work differently.

System Type	How It Works	Best Suited To
Electric storage	Heats and stores water in a tank	Simple replacements and homes without gas
Gas storage	Heats and stores water using natural gas or LPG	Homes already set up for gas that want stored hot water
Heat pump storage	Stores water and uses air heat to help heat it	Efficiency-focused homes with suitable outdoor space
Solar storage	Stores water heated by solar collectors and booster	Homes with suitable roof space and solar exposure
Instant gas	Heats water as it flows through the unit	Continuous flow hot water where gas supply and pressure suit
Instant electric	Heats water on demand using electricity	Small point-of-use applications

A storage system may be better if your household wants a stored supply ready during peak times. A continuous flow system may be better if you want compact on-demand hot water and the property can support the gas or electrical requirements.

Benefits of Hot Water Storage Systems

Stored Hot Water Ready for Use

The main benefit of a storage system is that hot water is kept ready in the tank. This can suit households with predictable morning or evening hot water use.

Multiple Energy Options

Storage systems are available in electric, gas, heat pump and solar formats. This gives households flexibility based on the energy source available at the property.

Familiar Replacement Pathway

Many homes already have electric or gas storage hot water. Replacing with a similar storage system can be simpler than changing system type, provided the old system was correctly sized and the location still suits.

Suitable for Different Household Sizes

Storage tanks are available in a range of capacities, from smaller household options through to larger family-sized systems.

Heat Pump and Solar Upgrade Options

Homes wanting improved energy efficiency may be able to compare heat pump or solar-style storage systems instead of replacing standard electric storage like-for-like.

Limitations of Hot Water Storage Systems

Storage hot water systems are not the perfect answer for every home.

Potential limitations include:

A tank can run out during high use
Oversizing can increase upfront cost
Undersizing can cause hot water shortages
Storage tanks need enough installation space
Heat loss can occur over time
Valves and compliance upgrades may be needed during replacement
Larger tanks can be harder to access in tight areas
Heat pumps need airflow, drainage and noise planning
Gas storage requires the correct natural gas or LPG model

The key is choosing the right system type and tank size for the household.

Choosing the Right Storage Tank Size

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

A tank that is too small may run out during peak use. A tank that is too large may cost more than needed and may not suit the home’s usage pattern.

When choosing size, consider:

Number of people in the home
Number of bathrooms
Shower length
Bath use
Kitchen and laundry habits
Whether multiple showers run at once
Morning and evening peak demand
Existing system size
Whether the old system ran out of hot water
Available energy source
Recovery rate
Installation space

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

For heat pumps, many homes compare 250L to 280L systems, with larger households considering 280L-plus options.

For gas storage, many homes compare 130/135L and 160/170L categories depending on household demand and gas setup.

Small Household Storage Hot Water

Small households may suit:

Smaller electric storage systems
Selected 250L electric storage systems depending on usage
Smaller gas storage where gas is available
Selected heat pumps if outdoor space and airflow suit

Avoid oversizing unless the home has unusually high hot water use or future household growth is expected.

Family Storage Hot Water

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

Common options include:

250L electric storage for moderate demand
315L electric storage for higher demand
400L electric storage for larger households
Medium heat pump storage systems
Gas storage where natural gas or LPG is suitable

If the existing system regularly runs out, review the size and system type before ordering a replacement.

High-Demand Homes

Larger or high-demand homes may need:

315L or 400L electric storage
Larger heat pump systems
Larger gas storage systems
Installer review of pipework, pressure, access and recovery needs

Do not choose the largest tank automatically. The best option depends on usage pattern, recovery rate, installation space and energy source.

Electric Storage vs Heat Pump Storage

Electric storage and heat pump storage both use electricity, but they are not the same.

Option	Best Suited To	Key Considerations
Electric storage	Simple replacement, lower upfront product price, homes without gas	Running cost can be higher depending on tariff and usage
Heat pump storage	Homes focused on reducing hot water energy use	Needs outdoor airflow, drainage, electrical suitability and noise planning

A heat pump may be worth comparing if you are replacing an old electric storage system and the home has a suitable outdoor location.

However, standard electric storage may still suit some homes that want a simple replacement or do not have the right location for a heat pump.

Gas Storage vs Instant Gas

Gas storage and instant gas are both gas hot water options, but they work differently.

Gas storage keeps hot water ready in a tank. Instant gas hot water systems heat water only as it passes through the unit.

Gas storage may suit homes that:

Prefer stored hot water
Already have a gas storage system
Want a familiar tank-style replacement
Have suitable outdoor space for a tank

Instant gas may suit homes that:

Want continuous flow hot water
Want a compact wall-mounted unit
Have suitable gas supply and water pressure
Want to compare 16L, 20L and 26L flow rates

For larger instant gas options, browse 26L instant gas hot water systems. For any gas system, the correct natural gas or LPG model must be selected.

Installation Requirements to Check Before Ordering

Hot water storage systems involve plumbing, water pressure, valves, drainage, electrical work and sometimes gas work. Do not install or modify a system yourself.

Before ordering, confirm:

Correct system type
Correct tank size
Correct gas type if choosing gas
Electrical requirements if choosing electric or heat pump
Installation location
Access for delivery and installation
Base or slab condition
Drainage and overflow points
Tempering valve requirements
Pressure limiting valve requirements
Expansion control valve requirements
Existing pipework condition
Heat pump airflow and noise placement
Whether compliance upgrades are needed

A licensed plumber, gas fitter or electrician may be required depending on the system and work involved.

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

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

It does not usually include:

Installation labour
New valves
Electrical work
Gas work
Pipework changes
Drainage changes
Tempering valve upgrades
Pressure limiting valve upgrades
Expansion control valves
Condensate drainage for heat pumps
Old unit removal
Disposal
Compliance upgrades
Concrete bases or slab work
Relocation of the system

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

Supply-Only vs Supplied-and-Installed

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
You know the right tank size and model
The correct gas type has been selected
Electrical requirements have been checked
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, location and installation requirements.

Brisbane and Gold Coast Considerations

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

Common local considerations include:

Older electric storage replacements
Homes comparing electric storage with heat pump upgrades
Natural gas vs LPG availability
Outdoor gas storage positioning
Tight side access
Drainage and overflow points
Heat pump airflow and noise placement
Solar-friendly heat pump timing
Ageing valves and pipework
Larger family hot water demand

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

Rebates, STCs and Incentives

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

These incentives can change, so check current eligibility before ordering or budgeting around a rebate.

A rebate may improve the value of an upgrade, but the system still needs to suit the household and installation location. Do not choose a product only because it has an incentive attached.

Brand Options to Compare

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

Brand matters, but the right system type, tank size, gas type, installation location and site suitability matter more than brand alone.

Common Mistakes When Choosing a Hot Water Storage System

Replacing the Same Size Without Checking Demand

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

Choosing Only by Product Price

The cheapest unit upfront may not be the cheapest long term once running costs, installation extras and suitability are considered.

Oversizing the Tank

A bigger tank can cost more upfront and may not suit the household’s usage pattern.

Ordering the Wrong Gas Type

Natural gas and LPG units are different. Always choose the correct gas type.

Choosing Heat Pump Without Checking Location

Heat pumps need airflow, outdoor space, drainage, access and sensible noise placement.

Forgetting About Valves and Drainage

Storage systems may need valve upgrades, overflow management or drainage changes during replacement.

Assuming Supply-Only Includes Installation

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

Before Ordering Checklist

Before ordering a hot water storage system, confirm:

Number of people in the home
Number of bathrooms
Shower habits
Peak hot water demand
Existing system type
Existing system size
Whether the old system ran out of hot water
Electric, natural gas or LPG availability
Correct gas type
Electrical requirements
Water pressure
Heat pump airflow and drainage
Outdoor or indoor suitability
Access for delivery and installation
Drainage and overflow requirements
Whether new valves may be needed
Whether rebates or STCs may apply
Whether supply-only or supplied-and-installed is the right option
Installer confirmation before buying supply only

Frequently Asked Questions

What is a hot water storage system?

A hot water storage system heats and stores water in a tank so it is ready for use when needed. Electric storage, gas storage, heat pump and solar hot water systems are all storage-style systems.

Is storage hot water better than instant hot water?

It depends on the home. Storage hot water can suit households wanting a stored supply, while instant gas can suit homes wanting continuous flow hot water without a large tank. Gas supply, water pressure, energy source and household demand all matter.

What size hot water storage 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 electric storage sizes include 250L, 315L and 400L.

Is electric storage hot water good?

Electric storage can be a practical option for homes without gas or for simple replacements. Running cost depends on tariff, usage and system size.

Is gas storage hot water good?

Gas storage can suit homes already set up for natural gas or LPG that want stored hot water. The correct gas type and licensed gas fitting are essential.

Is a heat pump a storage hot water system?

Yes. A heat pump stores hot water in a tank, but it uses heat from the surrounding air to help heat the water.

Can storage hot water work with solar?

Solar hot water uses storage tanks with roof-mounted collectors and usually includes a booster. Some electric and heat pump systems may also work well with rooftop solar electricity where timing and usage suit.

Can I install a hot water storage system myself?

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

What is not included in supply-only hot water storage pricing?

Supply-only pricing generally excludes installation, valves, electrical work, gas work, pipework changes, drainage, old unit removal, disposal and compliance upgrades unless selected or clearly shown.

Final Word

A hot water storage system can be a reliable choice for Australian homes, but the right option depends on the household and property. Electric storage can suit simple replacements. Gas storage can suit homes already set up for natural gas or LPG. Heat pumps can suit energy-focused homes with suitable outdoor space. Solar storage can suit homes with strong roof suitability and booster planning.

Before ordering supply only, confirm the system type, tank size, gas type, electrical requirements, access, drainage, valves and compliance needs with your licensed installer. That way, your storage hot water system is matched properly to the home before it arrives.

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