Rheem 135L 4 Star Gas Hot Water System Review: Is It Worth Buying?

Feb 19, 2024

The Rheem 135L 4 Star gas hot water system is a popular choice for households comparing reliable gas storage hot water. It is often considered by small to medium families, rental properties and homeowners replacing an older gas storage unit with a similar-capacity system.

Unlike instant gas hot water, the Rheem 135L is a storage-style system. It heats and stores hot water in a tank, then reheats as hot water is used. That makes it a different buying decision from a continuous flow gas unit, electric storage system or heat pump hot water system.

This review explains who the Rheem 135L 4 Star gas hot water system may suit, what to check before ordering, how it compares with other hot water options, and when a different system may be a better fit.

You can compare Rheem Hot Water Systems, broader Gas Hot Water Systems, Instant Gas Hot Water Systems, Heat Pump Hot Water Systems and all Hot Water Systems online with Installed Today.

Quick answer: is the Rheem 135L 4 Star gas hot water system worth considering?

The Rheem 135L 4 Star gas hot water system can be worth considering if you already have a suitable gas storage hot water setup and want a practical replacement from a major hot water brand.

It may suit:

Small to medium households
Many 2 to 4 person homes
Homes already connected to natural gas
Properties replacing an older gas storage system
Rental properties
Homes that prefer stored hot water rather than instant gas
Customers wanting a recognised hot water brand
Supply-only customers with their own licensed gas fitter arranged
Eligible Brisbane and Gold Coast customers where supplied-and-installed options are available on selected products

It may not be the best choice if your home does not already have gas, if the household has very high hot water demand, if you want to move away from gas, or if a heat pump hot water system better suits your long-term energy plans.

What is the Rheem 135L 4 Star gas hot water system?

The Rheem 135L 4 Star is a gas storage hot water system. It stores hot water in a tank and uses gas to reheat the water as required.

A 135L gas storage system may suit homes that need:

Stored hot water
Gas recovery
A replacement for an existing gas storage tank
Mains pressure hot water where the installation supports it
A known brand option
Outdoor gas hot water replacement
A smaller to mid-size family hot water system

The important thing is to match the system to the household’s actual hot water demand, not just the size of the old tank.

Rheem 135L 4 Star key considerations

Before ordering, confirm:

Natural gas or LPG requirements
Existing system type
Existing system size
Number of people in the home
Number of bathrooms
Shower habits
Bath use
Gas pipe sizing
Water pressure
Installation location
Outdoor clearances
Valve requirements
Old unit removal
Disposal
Warranty terms
Supply-only or supplied-and-installed availability

Natural gas and LPG are not interchangeable, so the correct gas type must be selected.

Rheem 135L gas storage pros

The Rheem 135L 4 Star gas hot water system can offer several advantages when it suits the property.

Potential benefits include:

Recognised Rheem brand
Gas storage operation
Practical replacement for older gas storage systems
Stored hot water for household use
Suitable for many smaller to medium homes
Mains pressure performance where correctly installed
Outdoor installation suitability depending on model
Familiar operation for homeowners and tenants
May be simpler than changing system type
Supply-only ordering available where you have your own licensed installer
Supplied-and-installed options may be available on selected products in eligible Brisbane and Gold Coast areas

For many homes already set up for gas storage, replacing like-for-like can be more straightforward than changing to instant gas, electric or heat pump hot water.

Rheem 135L gas storage cons

The Rheem 135L is not automatically the best hot water system for every household.

Potential drawbacks include:

Requires suitable gas supply
Natural gas and LPG must not be mixed up
A 135L tank may not suit larger families
Stored hot water can run out after heavy use
Larger households may need more capacity
Gas work must be completed by a licensed gas fitter
It may not suit customers wanting to move away from gas
Heat pump hot water may be worth comparing for efficient electric upgrades
Installation extras can affect the final cost
Old valves, pipework or compliance issues can increase replacement cost

The main risk is assuming a 135L system will suit every home just because it is a known model.

Who is the Rheem 135L best for?

The Rheem 135L 4 Star gas hot water system may suit homes with moderate hot water demand.

It may be a good fit for:

Couples
Small families
Some 3 to 4 person households
One-bathroom homes
Some two-bathroom homes with moderate usage
Rental homes with suitable expected occupancy
Homes replacing an older 135L gas storage unit
Properties already set up for natural gas
Households that prefer gas storage over instant gas

It may not be ideal for:

Large families
Homes with multiple long showers
Homes with frequent bath use
Properties with 5 or more occupants
Homes wanting compact wall-mounted hot water
Customers wanting efficient electric hot water
Homes without gas
Homes where gas pipework or compliance is unsuitable

If the household regularly runs out of hot water, a larger system or different hot water type may be worth comparing.

Rheem 135L for 2 person homes

For a 2 person home, the Rheem 135L may be suitable where the property already has gas storage and daily hot water demand is moderate.

It may suit:

One bathroom homes
Couples
Small townhouses
Homes replacing an existing gas storage system
Properties with normal shower use
Homes where a larger tank is not needed

If the household has very low hot water use, a smaller system or different hot water type may also be worth comparing.

Rheem 135L for 3 to 4 person homes

The Rheem 135L is commonly considered for smaller family households, but suitability depends on usage.

Before choosing it for 3 to 4 people, check:

Number of showers per day
Shower length
Whether showers happen back-to-back
Bath use
Laundry hot water use
Dishwasher use
Morning and evening demand
Whether the old system ran out
Whether a larger gas storage, instant gas or heat pump system would suit better

For some 3 to 4 person homes, 135L may be enough. For higher-use homes, a larger system may be safer.

Rheem 135L for rental properties

The Rheem 135L may suit rental properties where the expected occupancy and bathroom count are moderate.

For rental properties, consider:

Number of bedrooms
Number of bathrooms
Likely tenant occupancy
Simple operation
Maintenance access
Warranty documentation
Existing gas setup
Replacement cost
Installation location
Future tenant use

A rental property should be sized for likely tenant demand, not only the current tenant.

Rheem 135L for Airbnb and short-stay homes

Short-stay properties can have unpredictable hot water use.

The Rheem 135L may suit smaller short-stay homes with moderate guest numbers, but it may not suit larger guest groups.

Before choosing it for Airbnb or short-stay accommodation, check:

Maximum guest count
Number of showers
Bath use
Laundry between bookings
Back-to-back shower use
Recovery expectations
Existing gas setup
Guest simplicity
Maintenance access

Hot water complaints can affect guest experience, so undersizing is risky.

Rheem 135L for renovations

A renovation is a good time to reassess hot water sizing and system type.

Before choosing the Rheem 135L during a renovation, confirm:

Final bathroom count
Fixture locations
Bath or shower changes
Gas supply
Gas pipe sizing
Outdoor location
Pipework route
Access after renovation
Drainage
Future household demand
Whether instant gas or heat pump hot water would suit better

Do not choose a replacement system before the final plumbing and gas layout is clear.

Natural gas vs LPG

The Rheem 135L gas hot water system must match the property’s gas type.

Natural gas and LPG are different. A natural gas model must not be treated as interchangeable with an LPG model.

Before ordering, check:

Whether the property has a natural gas meter
Whether the property uses LPG bottles
What the existing hot water unit label says
Whether the replacement model matches the gas type
Whether your licensed gas fitter has confirmed compatibility

Ordering the wrong gas type can delay installation and create extra cost.

Outdoor installation considerations

Gas storage hot water systems are often installed outdoors, but the location still needs to be suitable.

Check:

Stable base
Access
Clearance
Gas connection
Water pipework
Drainage
Relief valve discharge
Protection from impact
Weather exposure
Future service access
Compliance requirements

Do not assume the existing location automatically suits the new system.

Indoor installation considerations

Indoor gas hot water installations have stricter requirements and should only be considered where the model and installation setup are approved for indoor use.

Indoor gas installations may require careful attention to:

Ventilation
Flue requirements
Combustion air
Drainage
Safe discharge
Access
Gas compliance
Manufacturer requirements

A licensed gas fitter should confirm whether an indoor installation is suitable.

Rheem 135L energy efficiency

The Rheem 135L 4 Star gas hot water system is designed as a more efficient gas storage option than many older gas storage systems.

However, real-world running costs depend on the home.

Running costs may be affected by:

Gas price
Natural gas or LPG
Number of occupants
Shower length
Bath use
Laundry use
Temperature settings
Pipe run length
Maintenance
Water pressure
Household habits
Existing system efficiency

Avoid relying on one fixed annual savings figure. The same unit can cost different amounts to run in different homes.

Does the Rheem 135L provide enough hot water?

A 135L gas storage system can suit many smaller to medium households, but capacity depends on how the household uses hot water.

It may work well where:

Showers are moderate length
Bath use is limited
Occupancy is not too high
The home has one bathroom or moderate two-bathroom use
The system is correctly installed
The household is not using multiple hot water outlets heavily at once

It may struggle where:

Several people shower back-to-back
Baths are used regularly
Guests stay often
The home has high-flow shower heads
The household has grown since the old system was installed
Hot water is used heavily in morning and evening peaks

If the old 135L system regularly ran out, do not automatically replace it with the same size.

Mains pressure performance

Gas storage systems can provide strong hot water flow where the system, plumbing and water pressure support it.

Actual performance depends on:

Incoming water pressure
Pipe sizing
Valves
Tempering valve setup
Fixture flow rates
Number of outlets running
System condition
Installation quality

If hot water pressure is poor, the cause should be diagnosed before assuming the tank size is the problem.

Rheem 135L vs larger gas storage systems

A larger gas storage system may be worth comparing if the household has higher hot water demand.

The Rheem 135L may suit:

Smaller families
Moderate hot water use
One-bathroom homes
Some two-bathroom homes
Like-for-like gas storage replacement

A larger gas storage system may suit:

Larger families
More bedrooms
Higher shower demand
Bath use
Rental homes with higher likely occupancy
Homes where the old system ran out often

Bigger is not always better, but undersizing can be frustrating.

Rheem 135L vs instant gas hot water

The Rheem 135L stores hot water in a tank. Instant gas hot water heats water as it flows through the unit.

Feature	Rheem 135L gas storage	Instant gas hot water
Hot water type	Stored hot water	Continuous flow
Tank	Yes	No storage tank
Space	Requires tank space	Compact wall-mounted unit
Best for	Stored hot water with gas recovery	Homes wanting compact on-demand gas hot water
Gas supply	Required	Required
Water pressure	Important	Very important
Gas pipe sizing	Important	Critical
Simultaneous use	Depends on tank and recovery	Depends on flow rate, gas and water supply

Compare Instant Gas Hot Water Systems if you want compact continuous flow gas hot water instead of a storage tank.

Rheem 135L vs electric storage

Gas storage and electric storage both store hot water, but they use different energy sources.

Rheem 135L gas storage may suit:

Homes already using natural gas
Customers replacing older gas storage
Homes wanting gas recovery
Properties with suitable gas setup

Electric storage may suit:

Homes without gas
Units and townhouses
Simple electric replacement jobs
Properties with suitable electrical supply
Off-peak or controlled-load setups where appropriate

Compare Electric Hot Water Systems if your home does not have gas or if you want a simpler electric replacement.

Rheem 135L vs heat pump hot water

A heat pump hot water system uses electricity to transfer heat from surrounding air into stored water.

The Rheem 135L may suit:

Homes already using gas storage
Properties with suitable natural gas or LPG
Customers wanting a gas storage replacement
Households where heat pump location is not suitable

A heat pump may suit:

Homes replacing electric storage
Customers wanting an efficient electric option
Homes with rooftop solar
Properties with suitable outdoor airflow
Homes with suitable condensate drainage
Customers moving away from gas

Compare Heat Pump Hot Water Systems if your long-term goal is efficient electric hot water.

Rheem 135L vs Aquamax gas storage

Rheem and Aquamax are both commonly compared by customers looking at gas storage hot water.

When comparing Rheem Hot Water Systems with Aquamax Hot Water Systems, check:

Tank size
Gas type
Recovery performance
Warranty terms
Product dimensions
Installation location
Connection positions
Availability
Total replacement cost

The better choice depends on the exact model and the home’s hot water demand.

Rheem 135L vs Dux gas hot water

Dux is another major brand commonly compared against Rheem.

When comparing Rheem with Dux Hot Water Systems, check:

Gas storage vs electric or heat pump options
Tank capacity
Energy source
Warranty terms
Dimensions
Connection positions
Installation requirements
Household demand
Total cost

A lower product price is not always lower overall if installation extras are needed.

Rheem 135L vs Vulcan gas hot water

Vulcan Hot Water Systems may appeal to customers looking for value-focused hot water replacement options.

When comparing Rheem and Vulcan, check:

Tank size
Energy source
Warranty terms
Product price
Installation requirements
Household suitability
Availability
Total replacement cost

Rheem may appeal to customers wanting a recognised premium brand, while Vulcan may suit budget-conscious replacement jobs. The right choice depends on the home.

Rheem 135L vs Rinnai gas hot water

Rinnai Hot Water Systems are often compared with Rheem, especially for instant gas hot water.

The Rheem 135L may suit customers wanting gas storage.

Rinnai may be worth comparing if you want:

Instant gas hot water
Compact wall-mounted hot water
Continuous flow gas
Different gas hot water options
A recognised gas appliance brand

Compare system type first, then brand.

Installation requirements

A Rheem 135L gas hot water system should be installed by a licensed professional.

Important installation checks include:

Existing system type
Gas type
Gas pipe sizing
Water pressure
Installation location
Access
Valves
Drainage
Relief valve discharge
Tempering valve requirements
Pipework changes
Old unit removal
Disposal
Compliance requirements

A simple like-for-like replacement in one home may be more complex in another.

What can add cost to replacement?

The final replacement cost can increase if the job needs more than a standard swap.

Common extras may include:

New tempering valve
Pressure limiting valve
Expansion control valve where required
Gas pipework changes
Water pipework changes
Drainage work
Base or slab work
Difficult access
Old unit removal
Disposal
Compliance upgrades
LPG-specific requirements
Non-standard location changes

Compare the full replacement pathway, not just the unit price.

Supply-only Rheem 135L gas hot water

Supply-only ordering can suit customers who already have their own licensed gas fitter or plumber arranged.

Supply only may suit:

Builders
Renovators
Landlords
Property managers
Trade customers
Homeowners managing their own installation
Customers outside supplied-and-installed service areas

Supply-only product pricing generally does not include installation, valves, old unit removal, disposal, gas work, pipework changes, drainage, access upgrades or compliance upgrades unless clearly selected or included.

Before ordering supply only, your licensed installer should confirm the Rheem 135L suits the property.

Supplied-and-installed Rheem gas hot water

Supplied-and-installed options may be available on selected products in eligible Brisbane and Gold Coast service areas where shown.

This may suit customers who want the product and installation pathway arranged together.

Before ordering supplied and installed, check:

Service area eligibility
Existing system type
Installation inclusions
Natural gas or LPG
Valve requirements
Gas work
Water pipework
Old unit removal
Disposal
Drainage
Access
Base or slab condition
Compliance upgrades
Product suitability

Do not assume every possible site requirement is included. Check the selected product and installation options carefully.

Maintenance considerations

Gas storage hot water systems need periodic checks to support safe and reliable operation.

Maintenance may include:

Relief valve checks
Tempering valve checks
Burner inspection
Gas safety checks
Leak checks
Anode inspection or replacement where applicable
Pipework inspection
Water pressure checks
Drainage checks
General system inspection

Maintenance requirements depend on the model, water quality, installation conditions and manufacturer instructions.

Warranty considerations

Before choosing the Rheem 135L, check the current warranty terms on the product page and manufacturer documentation.

Review:

Cylinder warranty
Parts warranty
Labour coverage
Installation requirements
Maintenance requirements
Water quality exclusions
Pressure requirements
Gas type requirements
Licensed gas fitter requirements
Proof of purchase
Service process
What is and is not covered

Warranty coverage does not mean every issue is automatically covered. Incorrect installation, unsuitable water pressure, water quality problems, wrong gas type or missing documentation can affect claims.

Common mistake: choosing the wrong gas type

Natural gas and LPG are not interchangeable.

Always confirm the property’s gas type before ordering any gas hot water system.

Common mistake: replacing the same size when the old system ran out

If the old 135L system regularly ran out of hot water, replacing it with the same size may repeat the problem.

Reassess household demand before ordering.

Common mistake: comparing only the product price

The unit price is only one part of the total replacement cost.

Compare:

Product price
Delivery
Installation
Valves
Gas work
Pipework
Drainage
Old unit removal
Disposal
Compliance upgrades

Common mistake: ignoring water pressure

Water pressure affects hot water performance.

If pressure is poor, a licensed professional should check the cause before you choose a replacement.

Common mistake: assuming gas storage is always cheaper to run

Running cost depends on gas prices, household use, system condition and installation quality.

Heat pump hot water may be worth comparing if the home is suitable and you want an efficient electric upgrade.

Common mistake: DIY gas hot water installation

Gas hot water installation must be completed by a licensed gas fitter.

DIY gas work can create:

Gas leaks
Carbon monoxide risk
Fire risk
Water leaks
Warranty problems
Insurance issues
Non-compliant work
Poor performance
Safety hazards

Use the right licensed professional.

Final verdict: should you buy the Rheem 135L 4 Star gas hot water system?

The Rheem 135L 4 Star gas hot water system can be a solid option for small to medium households that already have a suitable gas storage setup and want a practical replacement from a recognised brand.

It is most likely to suit homes with moderate hot water use, suitable natural gas or LPG, compliant installation conditions and enough space for a storage tank.

It may not suit larger families, homes with heavy back-to-back shower use, properties without gas, or customers wanting to move toward heat pump hot water.

Before ordering, compare Rheem Hot Water Systems, broader Gas Hot Water Systems, Instant Gas Hot Water Systems, Heat Pump Hot Water Systems and all Hot Water Systems.

The right choice is not just the familiar brand or the same tank size you had before. It is the system that matches your gas type, household demand, installation location, water pressure and long-term cost expectations.

Long-tail FAQs

Is the Rheem 135L 4 Star gas hot water system good?

The Rheem 135L 4 Star gas hot water system can be a good option for small to medium homes that already use gas storage hot water and have moderate household demand.

How many people does a Rheem 135L suit?

It may suit many 2 to 4 person households, depending on shower habits, bath use, bathroom count and peak demand. High-use homes may need a larger system.

Is the Rheem 135L natural gas or LPG?

Rheem gas hot water systems may be available in different gas types depending on model. Natural gas and LPG are not interchangeable, so confirm the correct version before ordering.

Is 135L enough for a family?

A 135L gas storage system may suit some smaller families, but larger families or homes with long back-to-back showers may need a larger tank or different system type.

Is Rheem 135L better than instant gas?

Neither is always better. Rheem 135L gas storage suits homes wanting stored hot water. Instant gas suits homes wanting compact continuous flow hot water with suitable gas pipe sizing and water pressure.

Is Rheem 135L cheaper to run than electric hot water?

It depends on gas prices, electricity tariffs, household use and system condition. Do not rely on one fixed running cost figure for every home.

Should I choose Rheem 135L or heat pump hot water?

Choose Rheem 135L if gas storage suits the property. Compare heat pump hot water if you want an efficient electric option and have suitable outdoor airflow, drainage and electrical setup.

Can I install a Rheem 135L myself?

No. Gas hot water installation should be completed by a licensed gas fitter or suitable licensed professional.

What adds cost to Rheem 135L installation?

Common extras include valves, gas pipework changes, water pipework changes, old unit removal, disposal, drainage, access issues, base work and compliance upgrades.