Cheap Hot Water Systems Online: What to Watch Out For

Buying a cheap hot water system online can be a good way to compare product prices, but the cheapest unit is not always the best value. A low supply-only price may not include installation, valves, fittings, electrical work, gas fitting, old unit removal, disposal, delivery extras or compliance upgrades. At Hot Water Outlet, you can compare supply-only 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 compatible valves, pipework and fittings.

Quick Answer

Cheap hot water systems online can be worth comparing, but you need to check what is included and whether the system actually suits your property.

Before buying the cheapest option, check:

• System type

• Tank size or flow rate

• Natural gas or LPG if applicable

• Indoor or outdoor suitability

• Physical dimensions

• Electrical requirements

• Gas pipe requirements

• Heat pump airflow requirements

• Delivery cost and access

• Warranty conditions

• Required valves and fittings

• Whether licensed installation is needed

• Whether supply-only pricing excludes extra costs

A cheap electric hot water system may suit a simple like-for-like replacement. A cheap gas hot water system may not be cheap if the gas type, location or pipe sizing is wrong. A cheap heat pump hot water system may not suit if airflow, drainage or noise placement is poor.

Cheap Hot Water System Buyer Checklist

Why the Cheapest Hot Water System Is Not Always the Cheapest Installed Option

A hot water system price online may only show the product cost. That can be useful for comparison, but it does not show the full cost of getting hot water working legally and safely at the property.

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

A cheap unit can become expensive if it needs extra trade work, does not fit, has the wrong gas type, needs electrical upgrades or requires extra valves and pipework.

Cheap Electric Hot Water Systems Online

Electric hot water systems are often one of the easiest categories to compare online because they are available in many common tank sizes.

Cheap electric storage systems may suit when:

• You are replacing electric storage like-for-like

• The existing size worked well

• The electrical circuit is suitable

• The tank fits the same space

• You want a simple storage system

• Noise needs to be minimal

• There is no gas connection

What to Watch Out For

Before choosing the cheapest electric system, check:

• Tank size

• Element rating

• Indoor or outdoor rating

• Dimensions

• Connection positions

• Electrical circuit requirements

• Switchboard capacity

• Off-peak or controlled-load setup

• Safe tray requirements if indoors

• Drainage and relief valve discharge

• Required valves and fittings

A cheap 125L system may not suit a family that needs 250L or 315L. A cheap tank may also cost more to install if the connections, dimensions or electrical requirements do not match the existing setup.

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

Cheap Heat Pump Hot Water Systems Online

Heat pump hot water systems can be attractive because they are often compared for energy efficiency, but cheap heat pumps need careful checking.

A heat pump is not just a standard electric tank. It needs outdoor airflow, condensate drainage, noise consideration, electrical supply and enough space around the unit.

Cheap Heat Pumps May Suit When

• The site has suitable outdoor airflow

• Condensate drainage can be managed

• Noise placement is acceptable

• The electrical setup is suitable

• The tank size suits the household

• Access for delivery is practical

• Warranty conditions are understood

• The buyer wants an efficient electric option

What to Watch Out For

Before choosing the cheapest heat pump, check:

• Tank size

• Compressor and component warranty

• Outdoor airflow requirements

• Clearance requirements

• Condensate drainage

• Relief valve drainage

• Noise level and placement

• Distance to bedrooms and neighbours

• Electrical requirements

• Backup element setup

• Access for servicing

• Rebate or STC eligibility

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 just because the product is a heat pump.

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

Cheap Gas Hot Water Systems Online

Gas hot water systems can suit homes that already have gas storage or suitable gas services.

However, cheap gas systems need careful checking because natural gas and LPG are not interchangeable.

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

What to Watch Out For

Before buying a cheap gas hot water system, check:

• Natural gas or LPG

• Gas storage or instant gas

• Tank size or flow rate

• Indoor or outdoor rating

• Flue and ventilation requirements

• Gas pipe sizing

• Gas meter capacity

• LPG bottle and regulator setup

• Drainage and relief valve discharge

• Access for replacement

• Required valves and fittings

• Licensed gas fitting requirements

A cheap gas unit can become the wrong purchase if the gas type is incorrect or the location is not suitable.

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

Cheap Instant Gas Hot Water Systems Online

Instant gas hot water systems, also called continuous flow gas systems, are often compared by flow rate.

Cheap instant gas units may suit when:

• The property already has instant gas

• The correct gas type is selected

• The flow rate suits the home

• Gas pipe sizing is suitable

• Water pressure is suitable

• The existing location is compliant

• Controller requirements are understood

What to Watch Out For

Before buying a cheap instant gas unit, check:

• Natural gas or LPG

• 16L, 20L, 26L or other flow rate

• Number of bathrooms

• Whether showers run at the same time

• Water pressure and minimum flow

• Gas pipe sizing

• Gas meter or LPG regulator capacity

• Controller compatibility

• Power point requirements

• Clearances to windows, doors and vents

• 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.

Cheap Instant Electric Hot Water Systems Online

Instant electric hot water systems can look cheap because they are compact and do not store hot water. However, they are not always suitable for whole-home hot water.

Instant electric systems can need significant electrical capacity, especially for showers and high-flow fixtures.

Instant Electric May Suit

• Hand basins

• Kitchenettes

• Small studios

• Single outlet applications

• Low-flow point-of-use hot water

• Detached offices or small secondary spaces

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

• Sites where switchboard upgrades are not practical

Before buying cheap instant electric, confirm the electrical requirements with a licensed electrician.

Cheap Does Not Mean Correct Size

One of the biggest mistakes is buying a smaller system because it is cheaper.

A small tank may cost less upfront, but it may not provide enough hot water. This can lead to short showers, complaints from tenants, poor performance in winter or repeated booster use.

Storage Size Guide

Instant Gas Flow Guide

Choose the system based on household demand, not just the lowest price.

Cheap Does Not Mean Easy to Install

A cheap product can still be expensive to install if it needs extra work.

Extra costs may come from:

• Different pipe connection positions

• Bigger or heavier tank

• Difficult access

• Stairs

• Tight side paths

• Poor drainage

• Missing safe tray

• Electrical circuit changes

• Switchboard upgrades

• Gas pipe upgrades

• LPG regulator changes

• Controller wiring

• New base or slab

• Valves and fittings

• Compliance upgrades

This is why comparing product price alone can be misleading.

Watch Out for Wrong Gas Type

Gas hot water systems must match the property gas type.

Do not guess between natural gas and LPG.

Check:

• Existing appliance label

• Gas meter

• LPG bottles

• Product listing

• Previous paperwork

• Licensed gas fitter confirmation

Buying the wrong gas type can make the system unsuitable, delay installation and create return issues.

Watch Out for Heat Pump Placement

A cheap heat pump can be poor value if the property does not suit heat pump installation.

Check:

• Outdoor airflow

• Clearance to walls and fences

• Noise placement

• Condensate drainage

• Relief valve drainage

• Distance to bedrooms

• Distance to neighbours

• Electrical supply

• Base or slab

• Service access

Heat pumps are not suitable for every cupboard, garage, balcony or side path.

Watch Out for Delivery Costs and Access

Hot water systems are large, heavy products. Delivery conditions matter.

Before ordering, check:

• Delivery cost

• Delivery area

• Delivery timeframe

• Whether someone must be home

• Where the system will be delivered

• Whether stairs are included

• Whether difficult access is included

• Whether regional delivery costs more

• Whether the system can fit through gates, doors or lifts

• Whether the old unit removal is included

A cheap system may not be cheap if delivery costs or access problems are not considered.

Watch Out for Missing Valves and Fittings

Many online hot water system prices do not include the valves and fittings needed for installation.

Depending on the system, 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

• Gas isolation valve

• Connection fittings

• Pipework materials

• Safe tray parts

• Heat pump condensate drainage materials

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

Watch Out for Warranty Conditions

A cheap hot water system should still be checked for warranty conditions.

Before buying, check:

• Tank warranty

• Parts warranty

• Compressor warranty for heat pumps

• Labour warranty, if any

• Domestic or commercial use 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.

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

Watch Out for Unsupported Savings Claims

Be careful with claims that make a system sound cheaper than it really is.

Watch for:

• Savings claims without context

• Rebate claims without current eligibility

• Running cost claims without usage assumptions

• Warranty claims without conditions

• “Easy install” claims without site checks

• “Same size replacement” claims without dimensions

• “Fits most homes” claims without access or compliance checks

Hot water system performance depends on the property, household usage, energy source, tariff, climate, installation quality and system type.

Watch Out for Rebate Assumptions

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

Eligibility may depend on:

• Product model

• Installer

• Property type

• Existing system type

• State or territory

• Purchase type

• Installation date

• Program rules

• Whether the buyer or installer claims the incentive

Do not assume the cheapest advertised price includes every rebate or that your property is eligible.

Cheap Hot Water Systems for Rentals

Cheap hot water systems are often considered for rental properties, but they still need to suit tenant demand and compliance requirements.

For rentals, check:

• Number of tenants

• Number of bathrooms

• Existing system type

• Reliability

• Warranty

• Access for servicing

• Ease of use

• Valve and fitting requirements

• Whether tenants may run out of hot water

• Licensed installation requirements

A very small or poorly matched system can create tenant complaints and repeat callouts.

Cheap Hot Water Systems for Apartments

Apartments need extra checks before buying cheap hot water online.

Check:

• Cupboard size

• Lift access

• Stair access

• Safe tray requirements

• Drainage

• Body corporate rules

• Indoor or outdoor rating

• Electrical supply

• Gas type if applicable

• Heat pump airflow if considering heat pump

• Noise restrictions

• Delivery access

A cheap system that does not fit through the apartment or into the existing cupboard can create major problems.

Cheap Hot Water Systems for Larger Homes

For larger homes, the cheapest system is often not the right system.

Larger homes may need:

• Bigger electric storage

• Larger heat pump

• Higher-flow instant gas

• Multiple systems

• Better recovery

• Correct gas pipe sizing

• Proper electrical supply

• More careful drainage and valve setup

If a large family buys a small cheap tank, it may run out of hot water during peak use.

When a Cheap Hot Water System May Be Fine

A cheaper hot water system may be suitable when:

• It matches the existing system type

• It is correctly sized

• It fits the existing space

• The electrical or gas supply suits

• The installation location is suitable

• Access is straightforward

• Warranty conditions are acceptable

• Required valves and fittings are allowed for

• Licensed installation is arranged

• The buyer understands what supply-only means

Cheap is not automatically bad. The issue is whether the system is suitable.

When Paying More May Be Better Value

A more expensive system may be better value when it provides:

• Better size match

• Better warranty conditions

• Better energy efficiency

• Better recovery

• Better brand support

• Better fit for the existing location

• Better suitability for solar power

• Better heat pump performance

• Better long-term reliability

• Lower risk of installation complications

The best value system is not always the lowest product price.

Best Brands to Compare for Cheap Hot Water Systems

The best brand depends on the system type, property and budget.

Vulcan

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

Dux

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

Rheem

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

Rinnai

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

Bosch

Bosch hot water systems are often compared for instant gas applications.

iStore

iStore hot water systems are commonly compared by buyers looking at heat pump hot water options.

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 where the site conditions suit.

Common Mistakes When Buying Cheap Hot Water Online

Buying Only on Price

The cheapest product may not be suitable for the home.

Ignoring Supply-Only Exclusions

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

Buying the Wrong Gas Type

Natural gas and LPG are not interchangeable.

Choosing Too Small a Tank

A cheap small tank may run out of hot water quickly.

Not Checking Dimensions

The unit may not fit the existing space, safe tray or access path.

Choosing Heat Pump Without Checking Airflow

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

Buying Instant Electric for Whole-Home Use Without Checking Power

Instant electric may need significant electrical capacity.

Forgetting Drainage

Relief valve discharge and heat pump condensate need safe drainage.

Ignoring Warranty Conditions

Warranty can vary by component, model and installation conditions.

Not Allowing for Valves and Fittings

Replacement systems often need extra parts for safe and compliant installation.

Buyer Checklist Before Ordering a Cheap Hot Water System Online

Before ordering, 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

• LPG regulator setup 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: Cheap Hot Water Systems Online

Are cheap hot water systems worth buying?

Cheap hot water systems can be worth buying if they are correctly sized, suitable for the property, compatible with the existing services and installed by licensed tradespeople. The cheapest product is not always the cheapest final outcome.

What is the cheapest type of hot water system?

The cheapest product price is often a basic electric storage system, but total cost depends on installation, electrical work, valves, fittings, delivery, disposal and compliance requirements.

Are cheap heat pump hot water systems a good idea?

A cheap heat pump may be suitable if it has appropriate warranty, enough capacity and the site has suitable airflow, drainage, noise placement and electrical supply. Do not buy on price alone.

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

Check natural gas or LPG, system type, tank size or flow rate, gas pipe sizing, clearances, flue requirements, water pressure, controllers and licensed gas fitting requirements.

Can I buy a cheap hot water system and install it myself?

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

Why is supply-only cheaper than installed pricing?

Supply-only pricing is product pricing. Installed pricing may include labour, valves, fittings, old unit removal, disposal, electrical work, gas fitting, pipework changes and compliance upgrades.

Do cheap hot water systems have warranty?

Most hot water systems have warranty, but coverage varies by brand, model, component and conditions. Always check the warranty details before buying.

Do I need to buy valves and fittings separately?

Often, yes. The required valves and fittings depend on the system type, water pressure, location, compliance requirements and existing installation.

Can cheap systems still be reliable?

Some cheaper systems may be suitable for the right property and usage. Reliability depends on correct sizing, correct installation, water quality, usage, maintenance and product conditions.

Can Hot Water Outlet install the system?

Hot Water Outlet sells supply-only hot water systems and accessories online. Plumbing, gas fitting and electrical work must be completed by appropriately licensed tradespeople. Where appropriate, Hot Water Outlet may help organise quotes from reputable installers.

Final Thoughts

Cheap hot water systems online can be good value when the product is correctly sized, compatible with the property and installed legally by licensed tradespeople. The main risk is buying only on price and missing the extra costs.

Before ordering, check the system type, size, gas type, electrical requirements, dimensions, location, delivery, drainage, valves, fittings, warranty and installed cost.

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