Cheapest Hot Water Systems to Buy Online: How to Compare Value, Not Just Price

Jun 4, 2026

Finding the cheapest hot water system online can be useful when you are replacing an old unit, working to a budget or comparing supply-only options. But the cheapest system is not always the best choice if it is the wrong size, wrong energy type, wrong gas model, wrong flow rate or unsuitable for your home.

At Hot Water Outlet, you can compare hot water systems online, including electric hot water systems, gas hot water systems, instant gas hot water systems, heat pump hot water systems, instant electric hot water systems and common valves, pipework and fittings.

Quick Answer: What Is the Cheapest Hot Water System to Buy Online?

The cheapest hot water system to buy online is usually the lowest-priced system that still suits your home, energy source, household demand and replacement setup. Price alone should not decide the purchase.

As a general guide:

A smaller electric storage system may be cheaper than a larger family-sized unit.
A standard electric storage system may be cheaper upfront than a heat pump.
A lower-flow instant gas system may be cheaper than a higher-flow model.
A compact instant electric unit may be cheaper than a whole-home storage system, but it may only suit specific point-of-use applications.
A like-for-like replacement may be more cost-effective than changing system type.
The wrong hot water system can cost more overall if it needs extra changes or does not suit the property.

For most buyers, the best approach is to compare the relevant hot water systems category first, then choose the most affordable option that still matches the home.

Cheapest vs Best Value Hot Water System

There is a difference between the cheapest hot water system and the best value hot water system.

The cheapest system is the lowest-priced product at the time you are shopping. The best value system is the one that suits your property, meets household demand and avoids unnecessary compatibility issues.

A cheap hot water system may not be good value if:

It is too small for the household
It is the wrong gas type
It has the wrong flow rate
It does not physically fit the space
It has unsuitable connection positions
It does not match the current energy source
It needs extra changes to work
It is not suitable for the intended use
It requires accessories you did not budget for

A good-value system should match the home first. Price comes after suitability.

Cheapest Hot Water System Types Compared

System Type	Usually Cheaper When	Be Careful Of
Electric storage	You need a simple like-for-like tank replacement	Choosing the wrong tank size or power requirement
Gas storage	You already have gas storage and want a similar replacement	Natural gas vs LPG, tank size and recovery rate
Instant gas	You already have gas and want continuous flow	Choosing too low a flow rate
Heat pump	You want an efficient electric option and compare long-term value	Higher upfront cost and location requirements
Instant electric	You need a compact point-of-use system	Not always suitable for whole-home hot water

The cheapest category will depend on your current setup. A low-priced system in the wrong category is rarely a good deal.

Cheapest Electric Hot Water Systems

Electric hot water systems are often one of the first categories people compare when looking for affordable hot water replacement. They are common, familiar and available in a wide range of tank sizes.

Electric storage may be one of the cheaper options when:

The home already has an electric hot water tank
The existing tank size still suits the household
A like-for-like replacement is preferred
The current location works
The home does not have natural gas or LPG
A standard storage system is suitable

Electric systems are usually compared by tank capacity, recovery rate, pressure rating, dimensions and power requirements.

The cheapest electric hot water system is not always the smallest unit. A small tank may cost less upfront, but it may not suit a family home or a property with higher hot water demand.

Cheapest Electric Hot Water: What to Check

Before choosing a low-cost electric hot water system, check:

Tank capacity
Number of people in the home
Number of bathrooms
Shower habits
Whether the old tank ran out
Recovery rate
Power requirements
Dimensions
Connection positions
Indoor or outdoor suitability
Required valves and fittings

A low-priced electric system can be a strong choice when it matches the property. It can be a poor choice if it is undersized or does not fit the current setup.

Cheapest Gas Hot Water Systems

Gas hot water systems may be cost-effective for homes already using natural gas or LPG. Gas storage hot water can be practical when replacing an existing gas storage tank with a similar model.

Gas hot water may be a cheaper option when:

The home already has gas
The existing system is gas storage
The correct gas type is known
The current tank size suits the household
A like-for-like replacement is preferred
The location and connections are suitable

The biggest warning with cheap gas hot water is gas type. Natural gas and LPG systems are not interchangeable. A low price does not matter if the product is the wrong gas model for the property.

Cheapest Gas Hot Water: What to Check

Before choosing a low-cost gas hot water system, check:

Natural gas or LPG
Gas storage or instant gas
Tank capacity
Recovery rate
Dimensions
Connection positions
Pressure rating
Indoor or outdoor suitability
Existing gas supply
Required valves and fittings

If you are unsure whether the property uses natural gas or LPG, confirm this with a licensed gas fitter before ordering.

Cheapest Instant Gas Hot Water Systems

Instant gas hot water systems are often compared by buyers who want continuous flow gas hot water without a large storage tank.

Instant gas pricing is usually affected by flow rate, brand, gas type and controller compatibility. A lower-flow system may be cheaper than a higher-flow system, but it must still suit the home.

Instant gas may be a good-value option when:

The home already has natural gas or LPG
Continuous flow hot water is preferred
The selected flow rate suits the household
The unit location is suitable
A compact wall-mounted system is preferred
A like-for-like instant gas replacement is being considered

A cheap instant gas system may not be suitable if the flow rate is too low for the number of bathrooms or the way the home uses hot water.

Cheapest Instant Gas Hot Water: What to Check

Before choosing a low-cost instant gas system, check:

Natural gas or LPG
Flow rate in L/min
Number of bathrooms
Number of occupants
Shower demand
Whether multiple outlets run at once
Controller requirements
Dimensions
Connection positions
Outdoor location suitability
Required valves and fittings

A 16 L/min instant gas system, 20 L/min instant gas system and 26 L/min instant gas system are not designed for the same demand. The cheapest one may not be the right one.

Cheapest Heat Pump Hot Water Systems

Heat pump hot water systems usually cost more upfront than many standard electric storage tanks, but they are often compared for energy efficiency and longer-term value.

A heat pump may be worth comparing even if it is not the cheapest product price on the page. For some homes, a heat pump may be a better long-term option than standard electric storage, provided the property is suitable.

Heat pump hot water may be good value when:

The home is replacing old electric storage
Energy efficiency is a priority
Outdoor space is available
Airflow is suitable
Noise considerations can be managed
Tank size suits household demand
The product specifications match the property

A cheap heat pump is not good value if the home does not have a suitable location. Space, airflow, noise rating and access all matter.

Cheapest Heat Pump Hot Water: What to Check

Before choosing a low-cost heat pump hot water system, check:

Tank capacity
Household demand
Outdoor location
Airflow
Noise rating
Dimensions
Electrical requirements
Connection positions
Warranty information
Delivery access
Required valves and fittings

Heat pump systems should be compared by suitability, not price alone.

Cheapest Instant Electric Hot Water Systems

Instant electric hot water systems can sometimes appear cheaper than larger storage systems, but they are not always designed for the same purpose.

Instant electric hot water is generally more suited to specific point-of-use applications where the electrical requirements and flow demand match the product. It should not automatically be compared as a direct replacement for a whole-home storage tank.

Instant electric may be suitable when:

A compact point-of-use hot water supply is needed
The intended application matches the product
Electrical requirements can be met
Flow demand is low or specific
Storage space is limited

Before choosing instant electric based on price, confirm that it suits the intended use.

Cheapest Instant Electric Hot Water: What to Check

Before choosing a low-cost instant electric system, check:

Intended use
Flow demand
Electrical requirements
Product suitability
Connection requirements
Dimensions
Warranty information
Whether it is suitable for the application

A cheap instant electric unit can be useful in the right application, but it is not automatically the cheapest whole-home hot water option.

Cheapest Hot Water System for Like-for-Like Replacement

The cheapest practical replacement is often the system closest to what you already have.

Like-for-like replacement may be more cost-effective because the property already has the right energy source, location and general setup.

Common like-for-like replacements include:

Electric storage to electric storage
Gas storage to gas storage
Instant gas to instant gas
Heat pump to heat pump
Compact instant electric to compact instant electric

A like-for-like replacement may help avoid unnecessary changes, but it still needs to be checked properly. The new system should match the old system’s size, energy source, connection layout and household demand.

Cheapest Hot Water System for Small Homes

Small homes, units and townhouses may be able to use a smaller or more compact system than larger family homes. This can help reduce product cost, but only if the system still suits daily demand.

For small homes, compare:

Compact electric storage systems
Smaller heat pump options where suitable
Lower-flow instant gas systems where gas is available
Instant electric systems for suitable point-of-use applications

Before choosing a cheaper system for a small home, check:

Number of occupants
Number of bathrooms
Shower habits
Kitchen use
Laundry use
Available space
Current system type
Energy source
Access and delivery

Small home does not always mean small hot water demand. Choose based on usage.

Cheapest Hot Water System for Families

Families usually need more hot water than small households, so the cheapest suitable system may not be the lowest-priced product overall.

For families, compare:

Medium to larger electric storage systems
Family-sized heat pump hot water systems
Gas storage systems with suitable recovery
Instant gas systems with enough flow rate
Correct natural gas or LPG models
Required valves and fittings

A cheap undersized system may run out quickly or struggle during peak use. For families, correct sizing is usually more important than the lowest purchase price.

Cheapest Hot Water System for Rental Properties

For rental properties, price matters, but reliability and suitability matter too. A cheap system that does not suit the number of bedrooms, bathrooms or likely tenant demand can lead to problems.

For rentals, compare:

Existing system type
Number of bedrooms
Number of bathrooms
Expected tenant demand
Like-for-like replacement options
Brand recognition
Warranty information
Product availability
Required valves and fittings
Delivery access

The cheapest rental hot water system should still be practical, correctly sized and suitable for the property.

Cheapest Hot Water System for Renovations

Renovations can change hot water demand, so the cheapest replacement may not be the best option for the finished home.

A renovation may affect:

Number of bathrooms
Bath size
Shower demand
Kitchen layout
Laundry layout
System location
Pipework requirements
Energy source
Tank size
Flow rate

For renovations, compare the hot water system against the final layout, not just the current property. A cheaper system may not suit if you are adding a second bathroom or increasing demand.

Cheapest Hot Water Brands to Compare

Hot Water Outlet lists recognised hot water brands so buyers can compare systems by price, type, size and specifications.

Depending on the system category, you may want to compare:

Brand can affect price, but choosing by brand alone is not enough. Compare tank size, flow rate, gas type, dimensions, connection positions, warranty information and product suitability.

How to Compare Cheap Hot Water Systems Online

1. Start With the Correct Category

Do not compare every system type together at once. Start with the category that matches your home.

For example:

Electric tank replacement: compare electric hot water systems
Heat pump upgrade: compare heat pump hot water systems
Gas tank replacement: compare gas hot water systems
Continuous flow gas: compare instant gas hot water systems

2. Sort by Price, Then Check Suitability

Sorting by price can help you find affordable options, but the product still needs to suit the home.

Check the lowest-priced suitable models, not just the lowest-priced models overall.

3. Compare Size Properly

Storage systems are compared by tank capacity in litres. Instant gas systems are compared by flow rate in L/min.

Do not compare a small storage tank against a large continuous flow system as if they are the same type of product.

4. Check Energy Source

A cheap gas system is not suitable if the home does not have gas. A cheap electric storage system may not be the best choice if the home has suitable heat pump conditions and long-term efficiency is a priority.

5. Confirm Gas Type

If buying gas, confirm natural gas or LPG. This is essential.

6. Check Dimensions

A low-cost system still needs to fit the available space.

7. Check Connection Positions

Connection positions can affect replacement suitability. Compare the current setup with the new product specifications.

8. Check Required Accessories

A cheap unit may still require valves, fittings, pipework or accessories.

Browse valves, pipework and fittings if you are building a complete hot water order.

9. Check Delivery

Large tanks and heat pumps can be heavy and bulky. Delivery cost, availability and access should be checked before ordering.

10. Separate Product Price From Installation

Supply-only product pricing does not automatically include installation, labour, gas fitting, electrical work, disposal, pipework changes or compliance work unless clearly stated.

Why the Cheapest Hot Water System Can Cost More Later

A cheap hot water system can become expensive if it creates problems after purchase.

This can happen when:

The system is too small
The gas type is wrong
The flow rate is too low
The system does not fit
Extra fittings are needed
The existing connection layout does not match
The system is unsuitable for the intended use
Delivery access is difficult
A system type change requires extra work

The best way to avoid this is to compare the full setup before ordering. Product price is only one part of the decision.

Cheap Hot Water Systems and Warranty Information

Warranty information matters when comparing cheaper systems. A lower purchase price may still be suitable, but always check the warranty terms listed for the product.

Look for:

Cylinder warranty
Parts warranty
Labour warranty where applicable under manufacturer terms
Conditions and exclusions
Product registration requirements
Installation requirements
Whether the warranty suits the intended use

A cheap system with unclear suitability or poor fit for the home may not be good value, even if the upfront product price is low.

Cheap Hot Water Systems and Rebates

Some hot water systems, especially heat pumps, may be eligible for rebates or incentives depending on the current rules, product eligibility, location and installation requirements.

Rebates can change, so do not assume a product is eligible unless you have checked the current program conditions.

Before relying on a rebate, check:

Your state or territory
Product eligibility
Installer requirements
Customer eligibility
Application process
Current program availability
Whether the rebate is already included in a quoted price
Whether the product needs to be installed by an approved provider

A rebate can improve value, but it should not be the only reason to choose a product.

Cheap Hot Water Systems and Supply-Only Pricing

Hot Water Outlet sells supply-only hot water systems and accessories online. Supply-only pricing usually refers to the product itself, not installation.

Supply-only pricing usually does not include:

Plumbing labour
Gas fitting
Electrical work
Old unit removal
Disposal
Pipework changes
Valves and fittings unless listed
Compliance work
Site-specific requirements

Hot Water Outlet may help organise quotes from reputable installers where appropriate, but installation and connection work should be completed by licensed tradespeople.

Cheap Hot Water System Buyer Checklist

Before buying a cheap hot water system online, check:

Current system type
Current brand and model
Current tank size or flow rate
Electricity, natural gas or LPG
Household size
Number of bathrooms
Daily hot water demand
System category
Tank capacity if storage
Flow rate in L/min if instant gas
Recovery rate
Dimensions
Connection positions
Indoor or outdoor suitability
Heat pump airflow requirements if relevant
Noise rating if choosing heat pump
Power requirements
Gas requirements
Required valves
Required fittings
Delivery cost and access
Warranty information
Product specifications
Whether pricing is supply-only or installed

Common Mistakes When Buying the Cheapest Hot Water System

Choosing the Lowest Price Without Checking Size

A smaller tank or lower-flow system may be cheaper, but it may not suit the household.

Buying the Wrong Gas Type

Natural gas and LPG systems are not interchangeable. Always confirm gas type before ordering.

Ignoring Flow Rate

For instant gas, flow rate matters. A low-flow unit may not suit multiple bathrooms or family demand.

Ignoring Recovery Rate

For storage systems, recovery rate affects how quickly more hot water can be heated after use.

Forgetting Heat Pump Location Requirements

A cheap heat pump still needs suitable outdoor space, airflow and noise considerations.

Assuming Instant Electric Suits Whole-Home Use

Instant electric systems are often application-specific. Check whether the product suits the intended use.

Forgetting Valves and Fittings

The main unit price may not include everything required for the replacement.

Assuming Supply-Only Means Installed

Supply-only product pricing does not automatically include installation or connection work.

Not Checking Delivery Access

Hot water systems can be large and heavy. Delivery access should be checked before ordering.

Cheapest Hot Water System FAQs

What is the cheapest hot water system to buy?

The cheapest hot water system will depend on current product pricing, system type, size, brand and availability. A smaller electric storage system or compact unit may have a lower upfront price than larger systems, but the right choice depends on your home.

Is the cheapest hot water system worth buying?

The cheapest system can be worth buying if it suits the household, energy source, size, dimensions and replacement setup. It is not worth buying if it is the wrong type, too small or incompatible with the property.

Are electric hot water systems the cheapest?

Electric storage systems can be one of the more affordable categories upfront, especially for like-for-like replacement. However, price depends on tank size, brand, recovery rate, dimensions and product specifications.

Are gas hot water systems cheaper than electric?

Gas and electric pricing varies by system type, size, brand and specifications. Gas may be suitable where the property already has natural gas or LPG, while electric may suit homes without gas or existing electric tanks.

Is instant gas hot water cheap?

Instant gas hot water prices vary by flow rate, gas type, brand and controller options. Lower-flow units may cost less than higher-flow models, but the selected system must suit household demand.

Are heat pump hot water systems cheap?

Heat pump hot water systems usually cost more upfront than many standard electric storage systems, but they may offer better long-term value in suitable homes. Compare tank size, location requirements, airflow and product specifications.

Can I buy a cheap hot water system online?

Yes. You can compare and order supply-only hot water systems online through Hot Water Outlet. Make sure you check system type, size, gas type, dimensions, connection positions, accessories and delivery before ordering.

Does a cheap hot water system include installation?

Not unless clearly stated. Supply-only hot water system pricing usually refers to the product itself and does not automatically include plumbing, gas fitting, electrical work, disposal, valves, fittings or compliance work.

Do cheap hot water systems need valves and fittings?

Some hot water systems require valves, fittings or pipework depending on the replacement setup, pressure rating and connection layout. Browse valves, pipework and fittings and confirm compatibility before ordering.

What should I check before buying the cheapest hot water system?

Check the system type, tank size or flow rate, energy source, natural gas or LPG, dimensions, connection positions, household demand, required accessories, delivery access, warranty information and whether the product is suitable for your home.

Compare Affordable Hot Water Systems Online

The cheapest hot water system is only a good choice if it suits your home. Before ordering, compare the system type, tank capacity, flow rate, gas type, dimensions, connection positions, warranty information, valves, fittings and delivery requirements.

Browse hot water systems online with Hot Water Outlet to compare affordable electric, gas, instant gas, instant electric, heat pump and hot water accessory options by current product pricing and specifications.

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