Buy Hot Water Systems Online: Complete Guide

Buying a hot water system online can make it easier to compare prices, brands, sizes and system types before you order. The key is knowing what to check before you buy, because supply-only product pricing is not the same as total installed cost. At Hot Water Outlet, you can compare supply-only hot water systems online, including electric hot water systems, heat pump hot water systems, gas hot water systems, instant gas hot water systems, instant electric hot water systems and compatible valves, pipework and fittings.

Quick Answer

Yes, you can buy hot water systems online, but you need to check the system type, size, gas type, electrical requirements, installation location, delivery access, valves, fittings and licensed trade requirements before ordering.

Buying online works best when you already know what type of system you need or you are replacing a similar system.

For example:

• Replace electric storage with a similar electric hot water system

• Compare heat pump hot water systems where outdoor airflow, drainage and electrical setup suit

• Replace gas storage with a suitable gas hot water system

• Replace continuous flow gas with the correct instant gas hot water system

• Use instant electric hot water systems only where the electrical supply and application suit

Plumbing, gas fitting and electrical work must be completed by appropriately licensed tradespeople.

What to Check Before Buying Hot Water Online

Why Buy a Hot Water System Online?

Buying a hot water system online can help you compare options before committing.

It can be useful when you want to compare:

• Product prices

• Brands

• Tank sizes

• Heat pump models

• Gas and LPG options

• Electric storage systems

• Instant gas flow rates

• Product dimensions

• Warranty details

• Accessories and valves

• Delivery options shown at checkout

Online buying can also help you avoid rushed decisions when an old system fails. Instead of only looking at one replacement option, you can compare different system types and brands before ordering.

What Supply-Only Means

Hot Water Outlet sells supply-only hot water systems and accessories online. Supply-only means you are buying the product, not a full installed job.

Supply-only pricing usually does not include:

• Installation

• Plumbing labour

• Electrical work

• Gas fitting

• Old unit removal

• Disposal

• Valves

• Fittings

• Pipework changes

• Drainage work

• Switchboard upgrades

• Electrical circuit upgrades

• Gas upgrades

• Regulator changes

• LPG bottle work

• Controller wiring

• Compliance upgrades

• Concrete bases or platforms

• Delivery beyond what is shown at checkout

This is one of the most important things to understand before buying online. A cheap product price may not reflect the full cost of getting the system legally and safely installed.

Where appropriate, Hot Water Outlet may help organise quotes from reputable installers.

Step 1: Choose the Right Hot Water System Type

The first step is choosing the right system type.

Common options include:

• Electric storage

• Heat pump

• Gas storage

• Instant gas

• Instant electric

• Solar hot water replacement options

If you are replacing an existing system, the easiest starting point is to match the current system type. If you want to change system type, extra plumbing, gas fitting, electrical or compliance checks may be needed.

Electric Hot Water Systems Online

Electric hot water systems are a common online purchase because they are available in many tank sizes and suit many Australian homes, units, townhouses and rental properties.

Electric storage systems may suit when:

• The home already has electric storage

• There is no gas connection

• A simple tank-style system is preferred

• Noise needs to be minimal

• A like-for-like replacement is wanted

• There is enough space for a storage tank

Electric Hot Water Buyer Checks

Before buying electric hot water online, check:

• Tank size

• Element rating

• Indoor or outdoor rating

• Dimensions

• Electrical circuit requirements

• Switchboard capacity

• Off-peak or controlled-load setup

• Drainage and relief valve discharge

• Safe tray requirements if indoors

• Required valves and fittings

Common brands compared for electric storage include Rheem hot water systems, Dux hot water systems, Vulcan hot water systems and Stiebel Eltron hot water systems.

Heat Pump Hot Water Systems Online

Heat pump hot water systems are often compared by buyers looking for an efficient electric hot water option.

A heat pump uses electricity to move heat from the surrounding air into the water. It does not need natural gas or LPG, but it does need suitable outdoor airflow, drainage and electrical setup.

Heat pumps may suit when:

• The home has suitable outdoor space

• The home has solar power

• The buyer wants to move away from gas

• The property already has electric storage

• Energy efficiency is a priority

• Condensate drainage can be managed

• Noise placement is acceptable

Heat Pump Buyer Checks

Before buying a heat pump online, check:

• Tank size

• Outdoor airflow

• Clearance around the unit

• Noise placement

• Distance to bedrooms and neighbours

• Condensate drainage

• Relief valve drainage

• Electrical supply

• Existing base or slab

• Access for delivery

• Warranty conditions

• Rebate, STC or incentive eligibility

Brands commonly compared include iStore hot water systems, Stiebel Eltron hot water systems, Envirosun hot water systems and Emerald Energy.

Heat pump rebates, STCs and incentives can change and depend on the product, installer, property, purchase type and program rules. Do not assume a rebate applies without checking current eligibility.

Gas Hot Water Systems Online

Gas hot water systems may suit homes that already use gas storage or have a suitable gas setup.

Gas storage systems heat and store hot water in a tank. They may be considered when replacing an existing gas storage unit or where a tank-style gas setup is preferred.

Gas Storage Buyer Checks

Before buying gas storage online, check:

• Natural gas or LPG

• Existing tank size

• Indoor or outdoor rating

• Flue and ventilation requirements

• Gas pipe sizing

• Gas meter or LPG regulator capacity

• Drainage and relief valve discharge

• Dimensions

• Access for delivery

• Required valves and fittings

Natural gas and LPG are not interchangeable. A natural gas unit must not be connected to LPG unless it is specifically converted and approved by a licensed gas fitter, and an LPG unit must not be connected to natural gas unless the same applies.

Brands commonly compared include Rheem hot water systems, Dux hot water systems and Vulcan hot water systems.

Instant Gas Hot Water Systems Online

Instant gas hot water systems, also called continuous flow gas systems, heat water as it flows through the unit.

They may suit homes with natural gas or LPG where the gas supply, location and flow rate are suitable.

Instant gas may suit when:

• The property already has instant gas

• Natural gas or LPG is available

• Storage tank space is limited

• Strong recovery is important

• The correct flow rate is selected

• The appliance can be installed externally or correctly flued

Instant Gas Buyer Checks

Before buying instant gas online, check:

• Natural gas or LPG

• Flow rate, such as 16L, 20L or 26L

• Number of bathrooms

• Whether showers run at the same time

• Water pressure

• Minimum flow rate

• Gas pipe sizing

• Gas meter capacity

• LPG bottle and regulator setup

• Controller compatibility

• Power point requirements

• External clearances

• Flue requirements if internal

• Required valves and fittings

External gas hot water units are outdoor/external only unless the product is specifically designed and approved for internal or flued installation.

Common brands include Rinnai hot water systems, Bosch hot water systems and Rheem hot water systems.

Instant Electric Hot Water Systems Online

Instant electric hot water systems can suit selected applications, but they are not always suitable for whole-home hot water.

Instant electric systems heat water as it flows through the unit, but they can require significant electrical capacity.

Instant Electric May Suit

• Hand basins

• Kitchenettes

• Small studios

• Detached offices

• Single outlet applications

• Low-flow point-of-use hot water

Instant Electric May Not Suit

• Whole-home hot water

• Multiple bathrooms

• Back-to-back showers

• Large families

• High-flow shower use

• Homes with limited electrical capacity

Before buying instant electric online, confirm the required electrical supply with a licensed electrician.

Step 2: Choose the Right Size

Sizing is one of the biggest online buying risks.

A system that is too small may run out of hot water or struggle during peak use. A system that is too large may cost more than needed and take up extra space.

Storage Tank Sizing Guide

Instant Gas Flow Rate Guide

Do not choose by size alone. Shower flow rates, baths, household habits, recovery rate and simultaneous use all matter.

Step 3: Check Dimensions Before Ordering

Hot water systems with the same capacity can have different dimensions.

Before ordering, measure:

• Height

• Width

• Diameter

• Depth

• Clearance above the unit

• Clearance around valves

• Doorway access

• Cupboard opening

• Safe tray size

• Base or slab size

• Side access path

• Gate width

• Stair access

• Lift access for apartments

The replacement unit must fit the location and access path. A system can be correct on paper but still be difficult to move into place.

Step 4: Check Installation Location

The installation location affects which systems are suitable.

Common locations include:

• Outside wall

• Garage

• Laundry

• Cupboard

• Under stairs

• Balcony

• Apartment service area

• Side path

• Plant area

• Roof or split solar location

Location Checks

Check:

• Indoor or outdoor rating

• Weather exposure

• Airflow for heat pump

• Gas clearances

• Drainage

• Access for servicing

• Noise placement

• Base or slab

• Safe tray if indoors

• Distance to bathrooms and kitchen

• Future replacement access

Do not assume any hot water system can go in the same location. Heat pumps, gas systems and indoor storage tanks all have different requirements.

Step 5: Check Gas Type Before Buying

If buying gas, confirm the gas type before ordering.

Natural gas and LPG are not interchangeable.

Check:

• Gas meter

• LPG bottles

• Appliance data label

• Existing paperwork

• Product listing gas type

• Licensed gas fitter confirmation

Ordering the wrong gas type is one of the easiest mistakes to make when buying online.

Step 6: Check Electrical Requirements

Electrical requirements matter for:

• Electric storage

• Heat pump

• Instant electric

• Some instant gas systems

• Controller wiring

• Power points

• Timers

• Solar control setups

Check:

• Existing circuit

• Element rating

• Switchboard capacity

• Controlled-load or off-peak setup

• Timer setup

• Heat pump requirements

• Instant electric power demand

• Power point location

• Weatherproof power point if external

Electrical work must be completed by a licensed electrician.

Step 7: Check Plumbing and Drainage Requirements

Hot water systems need correct plumbing and drainage.

Check:

• Cold water connection

• Hot water connection

• Relief valve discharge

• Safe tray drain if indoors

• Heat pump condensate drain

• Existing pipework condition

• Water pressure

• Pressure limiting valve

• Tempering valve

• Pipework changes

• Safe discharge point

Poor drainage can cause water damage, nuisance discharge or compliance issues.

Step 8: Check Valves, Pipework and Fittings

A hot water system usually needs more than the unit itself.

You may need compatible valves, pipework and fittings, such as:

• Tempering valve

• Pressure limiting valve

• Duo valve

• Expansion control valve

• Isolation valve

• Non-return valve

• Relief valve drain materials

• Connection fittings

• Pipework materials

• Gas isolation valve

• Safe tray components

• Condensate drainage materials

Existing valves may be old, leaking, seized, non-compliant or unsuitable for the new unit.

Step 9: Check Delivery Details

Before buying online, check the delivery information shown at checkout.

Consider:

• Delivery area

• Delivery cost

• Delivery timeframe

• Whether someone needs to be available

• Access for unloading

• System weight

• Whether the delivery is to driveway, kerb, door or another location

• Whether stairs or difficult access are included

• Whether remote or regional delivery is available

• Whether old unit removal is included or excluded

A hot water system is large and heavy. Delivery access should be checked before ordering.

Step 10: Check Warranty Conditions

Warranty can vary by brand, model, component and installation conditions.

Before buying, check:

• Tank warranty

• Compressor warranty for heat pumps

• Parts warranty

• Labour warranty, if any

• Domestic or commercial conditions

• Water quality requirements

• Installation requirements

• Maintenance requirements

• Proof of purchase requirements

• Licensed installation requirements

Do not assume every part of the system has the same warranty period.

Step 11: Check Rebates, STCs and Incentives

Rebates, STCs and incentives may apply to some systems, especially heat pumps, but eligibility can change.

Eligibility may depend on:

• Product model

• Installer

• Property type

• State or territory

• Existing system type

• Purchase type

• Installation date

• Program rules

• Whether the buyer or installer claims the incentive

Do not rely on old rebate information. Always check current eligibility before buying.

Step 12: Arrange Licensed Trades

Buying the product online does not remove the need for licensed installation.

Depending on the system, you may need:

• Licensed plumber

• Licensed electrician

• Licensed gas fitter

• Solar hot water specialist

• Hydraulic designer for larger or commercial jobs

Plumbing, gas fitting and electrical work must be completed by appropriately licensed tradespeople.

Buying Online for Like-for-Like Replacement

A like-for-like replacement is usually the simplest online purchase.

Examples include:

• Electric storage to electric storage

• Gas storage to gas storage

• Instant gas to instant gas

• Heat pump to heat pump

Like-for-like may suit when:

• The old system worked well

• The size was suitable

• The location is compliant

• The energy source is staying the same

• Access is suitable

• The household demand has not changed

Even then, check dimensions, gas type, electrical requirements, valve setup and drainage before ordering.

Buying Online When Changing System Type

Changing system type needs more care.

Examples include:

• Electric storage to heat pump

• Gas to electric

• Gas to heat pump

• Solar to heat pump

• Gas storage to instant gas

• Instant gas to electric storage

• Electric storage to instant electric

Changing system type may involve:

• New electrical circuit

• Switchboard changes

• Gas disconnection

• Gas pipe upgrades

• Plumbing changes

• Drainage changes

• Condensate drainage

• Controller wiring changes

• New base or slab

• Compliance upgrades

Before changing system type, check the full installed cost, not only the product price.

Best Brands to Compare When Buying Online

The best brand depends on system type, budget, household size and site suitability.

Rheem

Rheem hot water systems are commonly compared across electric storage, gas storage, instant gas and heat pump options.

Rinnai

Rinnai hot water systems are commonly compared for instant gas and continuous flow hot water systems.

Dux

Dux hot water systems are often compared for practical electric and gas storage replacements.

Bosch

Bosch hot water systems are commonly compared for instant gas systems.

Vulcan

Vulcan hot water systems are often considered for budget-conscious electric and gas storage options.

iStore

iStore hot water systems are commonly compared in the heat pump category.

Stiebel Eltron

Stiebel Eltron hot water systems may suit buyers comparing heat pump, electric and instant electric options.

Envirosun and Emerald Energy

Envirosun hot water systems and Emerald Energy are commonly compared for heat pump hot water systems where the site conditions suit.

Common Mistakes When Buying Hot Water Systems Online

Buying the Cheapest System Only

The cheapest product may not be the best value if it is undersized, unsuitable or expensive to install.

Ignoring Supply-Only Exclusions

Supply-only pricing does not usually include installation, valves, fittings, old unit removal, electrical work or gas fitting.

Ordering the Wrong Gas Type

Natural gas and LPG are not interchangeable.

Choosing the Same Size Without Checking Demand

If the old system ran out of hot water, buying the same size may repeat the issue.

Not Measuring the Space

The new unit may not fit the same location, even if the capacity is similar.

Choosing Heat Pump Without Checking Airflow

Heat pumps need suitable airflow, drainage and noise placement.

Buying Instant Electric Without Checking Power

Instant electric can require significant electrical capacity and may not suit whole-home hot water.

Assuming External Gas Units Can Go Indoors

External gas hot water units are outdoor/external only unless specifically designed and approved for internal or flued installation.

Forgetting Valves and Fittings

A replacement often needs new valves, fittings and compliance parts.

Not Checking Delivery Access

Hot water systems can be large and heavy. Tight access can affect delivery and replacement.

Buyer Checklist Before Ordering Online

Before buying a hot water system online, confirm:

• Existing system type

• Replacement system type

• Household size

• Number of bathrooms

• Whether showers run at the same time

• Whether the home has a bath

• Tank size or instant gas flow rate

• Natural gas or LPG if applicable

• Indoor or outdoor location

• Product dimensions

• Site access

• Delivery requirements

• Electrical circuit requirements

• Switchboard capacity

• Gas pipe sizing if applicable

• Heat pump airflow if applicable

• Drainage and discharge location

• Noise placement

• Required valves and fittings

• Warranty conditions

• Rebate or STC eligibility if applicable

• Licensed plumbing, electrical and gas fitting requirements

• Difference between supply-only price and installed cost

FAQ: Buying Hot Water Systems Online

Can you buy a hot water system online?

Yes. You can buy supply-only hot water systems online, but you need to check system type, size, dimensions, energy source, installation requirements, delivery access, valves and licensed trade requirements before ordering.

Is it cheaper to buy a hot water system online?

Buying online can make product prices easier to compare, but supply-only pricing is not the same as total installed cost. Installation, valves, fittings, electrical work, gas fitting and disposal may be separate.

What is the best hot water system to buy online?

The best hot water system to buy online depends on your home. Electric storage may suit simple replacements, heat pumps may suit energy-conscious homes with outdoor airflow, and instant gas may suit homes with suitable gas supply.

Can I install a hot water system myself?

No. Plumbing, gas fitting and electrical work must be completed by appropriately licensed tradespeople.

How do I know what size hot water system to buy?

Size depends on the number of people, bathrooms, shower habits, baths, recovery rate and system type. Do not choose only by copying the old system size if your usage has changed.

What should I check before buying a gas hot water system online?

Check natural gas or LPG, flow rate or tank size, gas pipe sizing, gas meter or LPG regulator capacity, clearances, flue requirements, controller compatibility and licensed gas fitting requirements.

What should I check before buying a heat pump online?

Check outdoor airflow, clearance, condensate drainage, relief valve drainage, noise placement, electrical supply, tank size, access and rebate eligibility.

Does supply-only pricing include installation?

No. Supply-only pricing generally does not include installation, plumbing labour, electrical work, gas fitting, valves, fittings, pipework changes, old unit removal, disposal or compliance upgrades.

Can Hot Water Outlet organise installation quotes?

Hot Water Outlet sells supply-only hot water systems and accessories online. Where appropriate, Hot Water Outlet may help organise quotes from reputable installers.

What happens if I order the wrong hot water system?

If the wrong system is ordered, it may not suit the property, gas type, electrical supply, location or access. That can lead to delays, extra costs or return issues. Check all details carefully before ordering.

Final Thoughts

Buying a hot water system online is a practical way to compare products, brands and prices, but the right choice depends on more than the product listing. Check the system type, size, gas type, electrical supply, dimensions, location, drainage, valves, delivery access and licensed trade requirements before ordering.

Browse hot water systems, compare electric hot water systems, heat pump hot water systems, gas hot water systems, instant gas hot water systems, instant electric hot water systems and compatible valves, pipework and fittings online at Hot Water Outlet.