Gas Hot Water System Price: What Affects the Cost Before You Buy

Oct 30, 2024

Gas hot water system prices can vary depending on the system type, brand, gas type, flow rate, tank size, installation location and whether you are ordering supply only or choosing an eligible supplied-and-installed option. A gas storage hot water system is priced differently from an instant gas hot water system, and a 16L continuous flow unit will not cost the same as a 26L model.

The cheapest gas hot water system upfront is not always the best value. The right system needs to match your household size, number of bathrooms, shower habits, natural gas or LPG supply, water pressure, gas pipe sizing, outdoor location and long-term hot water demand.

Installed Today makes it easy to compare and order gas hot water systems, instant gas hot water systems, 26L instant gas hot water systems and 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: How Much Does a Gas Hot Water System Cost?

The cost of a gas hot water system depends on the product and the installation pathway.

As a general guide:

Gas storage hot water systems are usually priced by tank size, gas type, brand and efficiency level
Instant gas hot water systems are usually priced by litres per minute, gas type and model features
26L instant gas systems generally cost more than smaller 16L or 20L units
Natural gas and LPG models must be selected correctly
Supply-only pricing usually covers the product only
Supplied-and-installed options are only available on selected eligible products and locations
Gas pipe upgrades, valves, drainage, electrical work, removal, disposal and compliance upgrades may be extra unless clearly selected or shown

Before ordering, check the current product page price and confirm full site requirements with your licensed gas fitter or installer.

What Affects Gas Hot Water System Prices?

Gas hot water pricing is affected by more than the unit itself. The final cost can change depending on the property and installation requirements.

Key price factors include:

Gas storage vs instant gas
Natural gas vs LPG
Tank size or flow rate
Brand and model
Energy efficiency rating
Outdoor or internal flued suitability
Gas pipe sizing
Water pressure
Installation location
Access for delivery and installation
Existing valves
Drainage and overflow requirements
Electrical connection for ignition or controls
Old unit removal
Disposal
Compliance upgrades
Whether the purchase is supply only or supplied and installed

A supply-only product price should not be compared directly with a full installed price. They are different purchase types.

Gas Storage Hot Water System Prices

Gas hot water systems include both gas storage and instant gas options. Gas storage systems heat water and keep it stored in a tank ready for use.

Gas storage hot water may suit homes that:

Already have natural gas or LPG
Want stored hot water ready for household use
Prefer a familiar tank-style replacement
Have suitable outdoor installation space
Have household demand that suits gas storage
Are replacing an older gas storage unit

Common gas storage categories include:

Gas storage pricing can be affected by tank size, efficiency rating, brand, gas type, installation access, existing pipework and whether valve or drainage upgrades are needed.

Popular gas storage options include:

Instant Gas Hot Water System Prices

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

Instant gas pricing is usually affected by:

Flow rate
Brand
Natural gas or LPG model
Temperature controller options
Gas pipe sizing
Water pressure
Outdoor location
Whether the old unit was storage or instant gas
Whether installation is like-for-like or more complex

Instant gas can suit homes that:

Want continuous flow hot water
Want a compact wall-mounted unit
Have suitable natural gas or LPG
Have suitable gas pipe sizing
Have suitable water pressure
Have suitable outdoor wall space

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

16L Gas Hot Water System Prices

A 16L instant gas hot water system is generally a smaller continuous flow option.

It may suit:

Smaller homes
One-bathroom homes
Lower shower demand
Smaller households
Replacing an existing 16L continuous flow unit

Relevant options include:

A smaller system may cost less than a larger unit, but it still needs to match household demand. Choosing too small can lead to poor hot water performance.

20L Gas Hot Water System Prices

A 20L instant gas hot water system may suit small-to-medium households with moderate hot water use.

It may suit:

Smaller families
Moderate shower demand
One-to-two bathroom homes, depending on usage
Homes replacing an existing 20L unit
Properties where a 26L system is not needed or not supported by site conditions

Relevant options include:

A 20L system can be a practical middle ground where household demand is moderate and the property setup suits the selected model.

26L Gas Hot Water System Prices

A 26L instant gas hot water system is often compared for larger households or homes with higher hot water demand.

It may suit:

Family homes
Higher shower demand
Some two-bathroom homes
Larger households
Homes wanting continuous flow gas hot water
Replacing an existing 26L continuous flow unit

Popular options include:

A 26L system may cost more than smaller instant gas units, and the site requirements matter more. Gas pipe sizing and water pressure must support the selected unit. A 26L gas hot water system is not automatically better if the property cannot supply enough gas or water flow.

Natural Gas vs LPG Pricing

Natural gas and LPG hot water systems are not interchangeable. You must choose the correct gas type before ordering.

Natural gas is supplied through a gas network connection
LPG is supplied through bottles or cylinders
Natural gas models and LPG models are different
Any approved gas conversion must be completed by a licensed gas fitter and only where the manufacturer allows it
Ordering the wrong gas type can make the unit unsuitable for the property

Pricing may differ between natural gas and LPG models depending on the product and availability. Running costs can also differ depending on local gas supply, bottle costs, household usage and the selected system.

Gas Storage vs Instant Gas Price Comparison

System Type	Product Cost	Installation Cost Factors	Best Suited To
Gas storage	Varies by tank size, brand and efficiency	Outdoor base, valves, drainage, gas connection, removal	Homes wanting stored hot water
16L instant gas	Usually lower than larger instant gas models	Gas type, water pressure, wall location, pipework	Smaller homes or lower-demand use
20L instant gas	Mid-range continuous flow option	Gas supply, water pressure, clearances, pipework	Small-to-medium households
26L instant gas	Usually higher than smaller instant gas models	Gas pipe sizing, water pressure, outdoor wall location	Higher-demand homes where site supports it

The best choice depends on household demand and site suitability, not just the lowest price.

Supply-Only Gas Hot Water Prices

Supply-only pricing generally means the listed price covers the product only. This can suit customers who already have a licensed gas fitter or installer organised.

Supply-only may suit you if:

Your installer has confirmed the correct model
The correct gas type has been selected
Gas pipe sizing has been checked
Water pressure has been checked
Outdoor location and clearances are suitable
Existing valves and drainage have been reviewed
You understand what is not included in the product price

Supply-only pricing usually does not include:

Installation labour
Licensed gas fitting
Electrical work
New valves
Pipework changes
Gas pipe upgrades
Drainage changes
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
Relocation of the system
Gas type conversion

Always confirm full site requirements before ordering supply only.

Supplied-and-Installed Gas Hot Water Prices

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 your address is eligible
Whether the selected gas hot water product is eligible
Whether the install is like-for-like
Whether the old system is gas storage or instant gas
Whether valves are included or extra
Whether gas pipework is included or extra
Whether electrical work is included or extra
Whether old unit removal is included
Whether disposal is included
Whether drainage or pipework changes are included
Whether compliance upgrades may be extra

Do not assume every gas system or every address has an installed option.

Installation Costs That Can Change the Final Price

Gas hot water installation costs can vary because every property is different.

Cost factors may include:

Like-for-like replacement vs system change
Switching from storage to instant gas
Moving the system location
Natural gas vs LPG setup
Gas pipe sizing
Water pressure issues
Existing valve condition
Drainage and overflow requirements
Electrical connection for controls or ignition
Outdoor wall suitability
Clearances around windows, doors and openings
Tight side access
Old unit removal
Disposal
Non-compliant existing installation
Extra pipework
Slab or base requirements

This is why a product-only price should never be treated as the final installed cost.

Gas Pipe Sizing and 26L System Costs

Gas pipe sizing is especially important for larger instant gas systems.

A 26L instant gas unit may suit some family homes, but it needs enough gas supply to perform properly. If the existing gas pipework is undersized, the installer may need to upgrade or alter the pipework, which can affect the final cost.

Before ordering a 26L unit, confirm:

Existing gas pipe size
Gas supply capacity
Distance from meter or LPG bottles
Number of other gas appliances
Water pressure
Hot water demand
Manufacturer requirements

Do not choose a 26L system based on flow rate alone.

Water Pressure and Flow Rate Costs

Instant gas systems need suitable water pressure and flow. If the property has poor pressure, older pipework, flow restrictions or faulty valves, the system may not perform as expected.

Before ordering, your installer should check:

Static water pressure
Flow rate
Pressure limiting valve
Existing pipework condition
Distance to bathrooms
Whether multiple outlets run at once
Whether the selected unit suits the available flow

Poor pressure should be diagnosed before buying a larger system.

Outdoor and Indoor Gas Unit Price Considerations

Most external gas hot water systems are designed for outdoor installation. External gas units must not be installed indoors unless the specific manufacturer model is approved for internal flued installation.

Indoor or internal-flued gas hot water systems may involve different product requirements, flue requirements and installation costs.

Before ordering, confirm:

Whether the unit is external or internal flued
Required clearances
Ventilation requirements
Flue requirements where applicable
Wall location
Access for servicing
Gas supply route
Water pipe route
Electrical connection where required

Choosing the wrong unit type can create costly installation problems.

Gas Hot Water Running Costs

Gas hot water running costs depend on:

Natural gas or LPG pricing
Household hot water use
Number of people in the home
Shower habits
System type
Storage vs instant gas
Efficiency rating
Pipework distance
Temperature settings
Maintenance
Other gas appliances in the home

Gas can be a practical option where the home already has suitable natural gas or LPG, but running cost should still be compared with electric storage and heat pump hot water options.

Gas Hot Water vs Electric Hot Water Cost

Electric hot water systems are often compared with gas hot water, especially when replacing an old system.

Electric storage may suit homes without gas or customers wanting a straightforward replacement. Gas hot water may suit homes already set up for natural gas or LPG.

Option	Upfront Cost	Running Cost Potential	Key Checks
Electric storage	Often lower upfront	Depends on tariff and usage	Tank size, electrical supply, drainage
Gas storage	Moderate	Depends on gas type and usage	Correct gas type, outdoor location, valves
Instant gas	Moderate	Can suit homes with gas supply	Gas pipe sizing, water pressure, gas type
Heat pump	Usually higher upfront	Can reduce electricity use in suitable homes	Airflow, drainage, noise, electrical supply

If the home does not have gas, electric storage or heat pump hot water may be more relevant.

Gas Hot Water vs Heat Pump Cost

A heat pump hot water system usually costs more upfront than a basic electric storage unit, but it may reduce electricity use in a suitable location.

Gas hot water may suit homes that:

Already have natural gas or LPG
Want gas storage or instant gas
Have suitable outdoor gas unit space
Have suitable gas pipe sizing and water pressure
Prefer continuous flow hot water

Heat pump hot water may suit homes that:

Want an electric hot water upgrade
Are replacing older electric storage
Have suitable outdoor space
Have clear airflow
Can manage condensate drainage
Want to pair hot water heating with rooftop solar where timing suits

If rebates, STCs or incentives are important, check current program rules. Standard gas hot water systems are not usually the main focus of heat pump or renewable-style incentives.

Gas Hot Water Rebates and Incentives

Rebates, STCs and incentives can change and may depend on the product, location, supplier pathway and current government or certificate program rules.

For many energy-efficiency programs, heat pump and solar-style hot water upgrades are more commonly associated with incentives than standard gas hot water systems.

Before budgeting around any rebate or discount, confirm:

Whether the selected gas hot water system qualifies
Whether your property qualifies
Whether the supplier or installer must be approved
Whether supply-only purchases qualify
Whether pre-approval is needed
Whether any customer contribution applies
Whether the incentive has changed

Do not choose a gas hot water system only because of an assumed rebate.

Gas Hot Water System Prices by Household Size

Small Households

Small households may compare:

16L instant gas systems
Smaller gas storage systems
Electric storage alternatives
Heat pump alternatives where outdoor space suits

Do not oversize if hot water demand is low.

Medium Households

Medium households may compare:

20L instant gas systems
26L instant gas systems where site supports it
130/135L gas storage
160/170L gas storage
Electric or heat pump alternatives

The right choice depends on bathrooms, showers and peak demand.

Larger Households

Larger households may need:

26L instant gas where gas pipe sizing and water pressure support it
Larger gas storage options
Installer review of gas supply, water pressure and fixture demand
Comparison with heat pump or larger electric storage where relevant

Do not assume the largest gas model is always the best answer.

Brisbane and Gold Coast Gas Hot Water Price Considerations

For Brisbane and Gold Coast homes, gas hot water cost is often affected by existing system type, access, outdoor location and gas supply.

Common local price factors include:

Natural gas vs LPG availability
Replacing gas storage with gas storage
Changing gas storage to instant gas
Gas pipe sizing for 26L systems
Outdoor wall location
Side access
Water pressure
Existing valve condition
Drainage and overflow
Old unit removal and disposal
Whether the product is eligible for supplied-and-installed options

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

Brand Differences and Price

Gas hot water brands vary by model range, product type, efficiency, features and availability.

Installed Today stocks major hot water brands including:

Brand matters, but the right gas type, size, flow rate, water pressure, pipe sizing and installation location matter more than brand alone.

Rheem Gas Hot Water Prices

Rheem hot water systems include electric, gas and heat pump options.

Rheem gas products to compare include:

Rheem may be worth comparing if you want both gas storage and instant gas options from a major brand.

Rinnai Gas Hot Water Prices

Rinnai hot water systems are commonly compared for instant gas hot water, especially Rinnai Infinity models.

Popular Rinnai gas options include:

Rinnai gas pricing depends on the selected flow rate, gas type, model and installation pathway.

Bosch Gas Hot Water Prices

Bosch hot water systems are often compared for compact gas continuous flow applications.

Relevant Bosch options include:

Bosch may suit some lower-demand gas hot water applications, depending on gas type, water pressure and household use.

Warranty and Price

Warranty terms can vary by brand, model, component and installation conditions. Always check the current product page and manufacturer documentation before ordering.

Warranty may depend on:

Correct licensed installation
Product type
Model-specific warranty terms
Water quality
Correct gas type
Maintenance requirements
Proof of purchase
Whether the system was installed according to manufacturer instructions

Do not rely on outdated third-party warranty information when comparing prices.

Common Mistakes When Comparing Gas Hot Water Prices

Comparing Product-Only and Installed Pricing

A supply-only product price is not the same as a full installed price.

Choosing the Cheapest Unit Only

A cheaper system may cost more long term if it is undersized, inefficient or unsuitable.

Ignoring Gas Type

Natural gas and LPG systems are different. Ordering the wrong model can create extra cost and delay.

Choosing 26L Instant Gas Without Checking Gas Pipe Sizing

A 26L unit can suit some family homes, but only where gas supply and water pressure support it.

Forgetting About Valves and Drainage

Replacement may involve valve upgrades, overflow changes or drainage work.

Assuming Rebates Apply

Rebates and incentives can change and may not apply to standard gas hot water systems.

Not Asking What Is Included

Always check whether removal, disposal, valves, electrical work, gas work and compliance upgrades are included or extra.

Before Ordering Checklist

Before ordering a gas 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
Natural gas or LPG availability
Correct gas type
Gas pipe sizing
Water pressure
Outdoor installation location
External or internal flued suitability
Access for delivery and installation
Drainage and overflow requirements
Whether new valves may be needed
Whether electrical connection is required
Whether removal and disposal are included
Whether supply-only or supplied-and-installed is the right option
Installer confirmation before buying supply only

Frequently Asked Questions

What is the average gas hot water system price?

Gas hot water system prices vary by brand, model, gas type, tank size, flow rate and installation pathway. Check the current product page for live supply-only pricing and confirm installation costs separately.

Is gas storage cheaper than instant gas?

Gas storage may be cheaper or more expensive depending on the model, tank size, brand and installation requirements. Instant gas pricing depends on flow rate, gas type and whether pipework upgrades are needed.

How much does a 26L gas hot water system cost?

The cost depends on the brand, gas type and whether you are ordering supply only or choosing an eligible installed option. Compare 26L options such as Rinnai B26 and Rheem 26L in natural gas and LPG models.

Is LPG gas hot water more expensive than natural gas?

Product and running costs can differ depending on the model, local gas pricing, bottle supply and household usage. Always choose the correct gas type for the property.

Does supply-only gas hot water pricing include installation?

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

What adds cost to gas hot water installation?

Common cost factors include gas pipe sizing, water pressure issues, valve upgrades, drainage changes, old unit removal, disposal, tight access, relocation, electrical work and non-compliant existing setups.

Is a 26L gas hot water system worth the extra cost?

A 26L system can be worth considering for some higher-demand homes, but only where gas pipe sizing and water pressure support it. Bigger is not better if the site cannot support the unit.

Are there rebates for gas hot water systems?

Rebates and incentives can change. Heat pump and solar-style hot water systems are more commonly linked with energy-efficiency incentives than standard gas systems. Check current eligibility before relying on a rebate.

Can I install a gas hot water system myself?

No. Gas hot water systems involve plumbing, gas fitting, water pressure, valves and compliance requirements. Gas work must be completed by a licensed gas fitter.

Final Word

Gas hot water system prices depend on more than the product on the page. Storage vs instant gas, natural gas vs LPG, flow rate, tank size, water pressure, gas pipe sizing, valves, drainage, access and installation inclusions all affect the final cost.

A cheap gas hot water system is not good value if it is the wrong gas type, too small for your household or not supported by your property’s gas supply. Compare the product price, installation pathway and long-term suitability before ordering.

If buying supply only through Installed Today, confirm the selected gas hot water system with your licensed gas fitter or installer first. 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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